diff --git a/src/gleam_community/maths/arithmetics.gleam b/src/gleam_community/maths/arithmetics.gleam
index d7e0e73..b44f80a 100644
--- a/src/gleam_community/maths/arithmetics.gleam
+++ b/src/gleam_community/maths/arithmetics.gleam
@@ -86,8 +86,8 @@ import gleam_community/maths/piecewise
 /// </div>
 ///
 pub fn gcd(x: Int, y: Int) -> Int {
-  let absx: Int = piecewise.int_absolute_value(x)
-  let absy: Int = piecewise.int_absolute_value(y)
+  let absx = piecewise.int_absolute_value(x)
+  let absy = piecewise.int_absolute_value(y)
   do_gcd(absx, absy)
 }
 
@@ -197,8 +197,8 @@ pub fn int_euclidean_modulo(x: Int, y: Int) -> Int {
 /// </div>
 ///
 pub fn lcm(x: Int, y: Int) -> Int {
-  let absx: Int = piecewise.int_absolute_value(x)
-  let absy: Int = piecewise.int_absolute_value(y)
+  let absx = piecewise.int_absolute_value(x)
+  let absy = piecewise.int_absolute_value(y)
   absx * absy / do_gcd(absx, absy)
 }
 
@@ -240,11 +240,11 @@ pub fn divisors(n: Int) -> List(Int) {
 }
 
 fn find_divisors(n: Int) -> List(Int) {
-  let nabs: Float = piecewise.float_absolute_value(conversion.int_to_float(n))
+  let nabs = piecewise.float_absolute_value(conversion.int_to_float(n))
   let assert Ok(sqrt_result) = elementary.square_root(nabs)
-  let max: Int = conversion.float_to_int(sqrt_result) + 1
+  let max = conversion.float_to_int(sqrt_result) + 1
   list.range(2, max)
-  |> list.fold([1, n], fn(acc: List(Int), i: Int) -> List(Int) {
+  |> list.fold([1, n], fn(acc, i) {
     case n % i == 0 {
       True -> [i, n / i, ..acc]
       False -> acc
@@ -288,7 +288,7 @@ fn find_divisors(n: Int) -> List(Int) {
 /// </div>
 ///
 pub fn proper_divisors(n: Int) -> List(Int) {
-  let divisors: List(Int) = find_divisors(n)
+  let divisors = find_divisors(n)
   divisors
   |> list.take(list.length(divisors) - 1)
 }
@@ -340,12 +340,10 @@ pub fn float_sum(arr: List(Float), weights: option.Option(List(Float))) -> Float
     [], _ -> 0.0
     _, option.None ->
       arr
-      |> list.fold(0.0, fn(acc: Float, a: Float) -> Float { a +. acc })
+      |> list.fold(0.0, fn(acc, a) { a +. acc })
     _, option.Some(warr) -> {
       list.zip(arr, warr)
-      |> list.fold(0.0, fn(acc: Float, a: #(Float, Float)) -> Float {
-        pair.first(a) *. pair.second(a) +. acc
-      })
+      |> list.fold(0.0, fn(acc, a) { pair.first(a) *. pair.second(a) +. acc })
     }
   }
 }
@@ -395,7 +393,7 @@ pub fn int_sum(arr: List(Int)) -> Int {
     [] -> 0
     _ ->
       arr
-      |> list.fold(0, fn(acc: Int, a: Int) -> Int { a + acc })
+      |> list.fold(0, fn(acc, a) { a + acc })
   }
 }
 
@@ -451,7 +449,7 @@ pub fn float_product(
       |> Ok
     _, option.None ->
       arr
-      |> list.fold(1.0, fn(acc: Float, a: Float) -> Float { a *. acc })
+      |> list.fold(1.0, fn(acc, a) { a *. acc })
       |> Ok
     _, option.Some(warr) -> {
       list.zip(arr, warr)
@@ -513,7 +511,7 @@ pub fn int_product(arr: List(Int)) -> Int {
     [] -> 1
     _ ->
       arr
-      |> list.fold(1, fn(acc: Int, a: Int) -> Int { a * acc })
+      |> list.fold(1, fn(acc, a) { a * acc })
   }
 }
 
@@ -563,7 +561,7 @@ pub fn float_cumulative_sum(arr: List(Float)) -> List(Float) {
     [] -> []
     _ ->
       arr
-      |> list.scan(0.0, fn(acc: Float, a: Float) -> Float { a +. acc })
+      |> list.scan(0.0, fn(acc, a) { a +. acc })
   }
 }
 
@@ -613,7 +611,7 @@ pub fn int_cumulative_sum(arr: List(Int)) -> List(Int) {
     [] -> []
     _ ->
       arr
-      |> list.scan(0, fn(acc: Int, a: Int) -> Int { a + acc })
+      |> list.scan(0, fn(acc, a) { a + acc })
   }
 }
 
@@ -665,7 +663,7 @@ pub fn float_cumulative_product(arr: List(Float)) -> List(Float) {
     [] -> []
     _ ->
       arr
-      |> list.scan(1.0, fn(acc: Float, a: Float) -> Float { a *. acc })
+      |> list.scan(1.0, fn(acc, a) { a *. acc })
   }
 }
 
@@ -717,6 +715,6 @@ pub fn int_cumulative_product(arr: List(Int)) -> List(Int) {
     [] -> []
     _ ->
       arr
-      |> list.scan(1, fn(acc: Int, a: Int) -> Int { a * acc })
+      |> list.scan(1, fn(acc, a) { a * acc })
   }
 }
diff --git a/src/gleam_community/maths/combinatorics.gleam b/src/gleam_community/maths/combinatorics.gleam
index f191eef..a3a4e7e 100644
--- a/src/gleam_community/maths/combinatorics.gleam
+++ b/src/gleam_community/maths/combinatorics.gleam
@@ -158,7 +158,7 @@ fn combination_without_repetitions(n: Int, k: Int) -> Result(Int, Nil) {
         False -> n - k
       }
       list.range(1, min)
-      |> list.fold(1, fn(acc: Int, x: Int) -> Int { acc * { n + 1 - x } / x })
+      |> list.fold(1, fn(acc, x) { acc * { n + 1 - x } / x })
       |> Ok
     }
   }
@@ -206,7 +206,7 @@ pub fn factorial(n) -> Result(Int, Nil) {
     1 -> Ok(1)
     _ ->
       list.range(1, n)
-      |> list.fold(1, fn(acc: Int, x: Int) -> Int { acc * x })
+      |> list.fold(1, fn(acc, x) { acc * x })
       |> Ok
   }
 }
@@ -310,7 +310,7 @@ fn permutation_without_repetitions(n: Int, k: Int) -> Result(Int, Nil) {
     }
     _, _ ->
       list.range(0, k - 1)
-      |> list.fold(1, fn(acc: Int, x: Int) -> Int { acc * { n - x } })
+      |> list.fold(1, fn(acc, x) { acc * { n - x } })
       |> Ok
   }
 }
@@ -620,18 +620,11 @@ fn do_list_permutation_with_repetitions(
 ///     </a>
 /// </div>
 ///
-pub fn cartesian_product(xset: set.Set(a), yset: set.Set(a)) -> set.Set(#(a, a)) {
+pub fn cartesian_product(xset: set.Set(a), yset: set.Set(b)) -> set.Set(#(a, b)) {
   xset
-  |> set.fold(
-    set.new(),
-    fn(accumulator0: set.Set(#(a, a)), member0: a) -> set.Set(#(a, a)) {
-      set.fold(
-        yset,
-        accumulator0,
-        fn(accumulator1: set.Set(#(a, a)), member1: a) -> set.Set(#(a, a)) {
-          set.insert(accumulator1, #(member0, member1))
-        },
-      )
-    },
-  )
+  |> set.fold(set.new(), fn(accumulator0: set.Set(#(a, b)), member0: a) {
+    set.fold(yset, accumulator0, fn(accumulator1: set.Set(#(a, b)), member1: b) {
+      set.insert(accumulator1, #(member0, member1))
+    })
+  })
 }
diff --git a/src/gleam_community/maths/elementary.gleam b/src/gleam_community/maths/elementary.gleam
index d5ff8af..491cab7 100644
--- a/src/gleam_community/maths/elementary.gleam
+++ b/src/gleam_community/maths/elementary.gleam
@@ -955,7 +955,7 @@ fn do_logarithm_10(a: Float) -> Float
 /// </div>
 ///
 pub fn power(x: Float, y: Float) -> Result(Float, Nil) {
-  let fractional: Bool = do_ceiling(y) -. y >. 0.0
+  let fractional = do_ceiling(y) -. y >. 0.0
   // In the following check:
   // 1. If the base (x) is negative and the exponent (y) is fractional
   //    then return an error as it will otherwise be an imaginary number
diff --git a/src/gleam_community/maths/metrics.gleam b/src/gleam_community/maths/metrics.gleam
index 9047b02..6c8959c 100644
--- a/src/gleam_community/maths/metrics.gleam
+++ b/src/gleam_community/maths/metrics.gleam
@@ -78,8 +78,8 @@ fn validate_lists(
     [], _ -> Error(Nil)
     _, [] -> Error(Nil)
     _, _ -> {
-      let xarr_length: Int = list.length(xarr)
-      let yarr_length: Int = list.length(yarr)
+      let xarr_length = list.length(xarr)
+      let yarr_length = list.length(yarr)
       case xarr_length == yarr_length, weights {
         False, _ -> Error(Nil)
         True, option.None -> {
@@ -87,7 +87,7 @@ fn validate_lists(
           |> Ok
         }
         True, option.Some(warr) -> {
-          let warr_length: Int = list.length(warr)
+          let warr_length = list.length(warr)
           case xarr_length == warr_length {
             True -> {
               validate_weights(warr)
@@ -169,9 +169,9 @@ pub fn norm(
       0.0
       |> Ok
     _, option.None -> {
-      let aggregate: Float =
+      let aggregate =
         arr
-        |> list.fold(0.0, fn(accumulator: Float, element: Float) -> Float {
+        |> list.fold(0.0, fn(accumulator, element) {
           let assert Ok(result) =
             piecewise.float_absolute_value(element)
             |> elementary.power(p)
@@ -182,28 +182,25 @@ pub fn norm(
       |> Ok
     }
     _, option.Some(warr) -> {
-      let arr_length: Int = list.length(arr)
-      let warr_length: Int = list.length(warr)
+      let arr_length = list.length(arr)
+      let warr_length = list.length(warr)
       case arr_length == warr_length {
         True -> {
           case validate_weights(warr) {
             Ok(_) -> {
-              let tuples: List(#(Float, Float)) = list.zip(arr, warr)
-              let aggregate: Float =
+              let tuples = list.zip(arr, warr)
+              let aggregate =
                 tuples
-                |> list.fold(
-                  0.0,
-                  fn(accumulator: Float, tuple: #(Float, Float)) -> Float {
-                    let first_element: Float = pair.first(tuple)
-                    let second_element: Float = pair.second(tuple)
-                    let assert Ok(result) =
-                      elementary.power(
-                        piecewise.float_absolute_value(first_element),
-                        p,
-                      )
-                    second_element *. result +. accumulator
-                  },
-                )
+                |> list.fold(0.0, fn(accumulator, tuple) {
+                  let first_element = pair.first(tuple)
+                  let second_element = pair.second(tuple)
+                  let assert Ok(result) =
+                    elementary.power(
+                      piecewise.float_absolute_value(first_element),
+                      p,
+                    )
+                  second_element *. result +. accumulator
+                })
               let assert Ok(result) = elementary.power(aggregate, 1.0 /. p)
               result
               |> Ok
@@ -353,7 +350,6 @@ pub fn minkowski_distance(
         |> list.map(fn(tuple: #(Float, Float)) -> Float {
           pair.first(tuple) -. pair.second(tuple)
         })
-
       norm(differences, p, weights)
     }
   }
@@ -472,7 +468,7 @@ pub fn chebyshev_distance(
       |> Error
     Ok(_) -> {
       list.zip(xarr, yarr)
-      |> list.map(fn(tuple: #(Float, Float)) -> Float {
+      |> list.map(fn(tuple) {
         { pair.first(tuple) -. pair.second(tuple) }
         |> piecewise.float_absolute_value()
       })
@@ -527,9 +523,7 @@ pub fn mean(arr: List(Float)) -> Result(Float, Nil) {
     _ ->
       arr
       |> arithmetics.float_sum(option.None)
-      |> fn(a: Float) -> Float {
-        a /. conversion.int_to_float(list.length(arr))
-      }
+      |> fn(a) { a /. conversion.int_to_float(list.length(arr)) }
       |> Ok
   }
 }
@@ -625,7 +619,7 @@ fn do_median(
 ///
 ///     pub fn example () {
 ///       // Degrees of freedom
-///       let ddof: Int = 1
+///       let ddof = 1
 ///
 ///       // An empty list returns an error
 ///       []
@@ -695,7 +689,7 @@ pub fn variance(arr: List(Float), ddof: Int) -> Result(Float, Nil) {
 ///
 ///     pub fn example () {
 ///       // Degrees of freedom
-///       let ddof: Int = 1
+///       let ddof = 1
 ///
 ///       // An empty list returns an error
 ///       []
@@ -762,8 +756,8 @@ pub fn standard_deviation(arr: List(Float), ddof: Int) -> Result(Float, Nil) {
 ///     import gleam/set
 ///
 ///     pub fn example () {
-///       let xset: set.Set(String) = set.from_list(["cat", "dog", "hippo", "monkey"])
-///       let yset: set.Set(String) =
+///       let xset = set.from_list(["cat", "dog", "hippo", "monkey"])
+///       let yset =
 ///         set.from_list(["monkey", "rhino", "ostrich", "salmon"])
 ///       metrics.jaccard_index(xset, yset)
 ///       |> should.equal(1.0 /. 7.0)
@@ -814,8 +808,8 @@ pub fn jaccard_index(xset: set.Set(a), yset: set.Set(a)) -> Float {
 ///     import gleam/set
 ///
 ///     pub fn example () {
-///       let xset: set.Set(String) = set.from_list(["cat", "dog", "hippo", "monkey"])
-///       let yset: set.Set(String) =
+///       let xset = set.from_list(["cat", "dog", "hippo", "monkey"])
+///       let yset =
 ///         set.from_list(["monkey", "rhino", "ostrich", "salmon", "spider"])
 ///       metrics.sorensen_dice_coefficient(xset, yset)
 ///       |> should.equal(2.0 *. 1.0 /. { 4.0 +. 5.0 })
@@ -871,8 +865,8 @@ pub fn sorensen_dice_coefficient(xset: set.Set(a), yset: set.Set(a)) -> Float {
 ///     import gleam/set
 ///
 ///     pub fn example () {
-///       let yset: set.Set(String) = set.from_list(["cat", "dog", "hippo", "monkey"])
-///       let xset: set.Set(String) =
+///       let yset = set.from_list(["cat", "dog", "hippo", "monkey"])
+///       let xset =
 ///         set.from_list(["monkey", "rhino", "ostrich", "salmon"])
 ///       // Test Jaccard index (alpha = beta = 1)
 ///       metrics.tversky_index(xset, yset, 1.0, 1.0)
@@ -894,15 +888,15 @@ pub fn tversky_index(
 ) -> Result(Float, Nil) {
   case alpha >=. 0.0, beta >=. 0.0 {
     True, True -> {
-      let intersection: Float =
+      let intersection =
         set.intersection(xset, yset)
         |> set.size()
         |> conversion.int_to_float()
-      let difference1: Float =
+      let difference1 =
         set.difference(xset, yset)
         |> set.size()
         |> conversion.int_to_float()
-      let difference2: Float =
+      let difference2 =
         set.difference(yset, xset)
         |> set.size()
         |> conversion.int_to_float()
@@ -949,9 +943,9 @@ pub fn tversky_index(
 ///     import gleam/set
 ///
 ///     pub fn example () {
-///       let set_a: set.Set(String) =
+///       let set_a =
 ///         set.from_list(["horse", "dog", "hippo", "monkey", "bird"])
-///       let set_b: set.Set(String) =
+///       let set_b =
 ///         set.from_list(["monkey", "bird", "ostrich", "salmon"])
 ///       metrics.overlap_coefficient(set_a, set_b)
 ///       |> should.equal(2.0 /. 4.0)
@@ -965,11 +959,11 @@ pub fn tversky_index(
 /// </div>
 ///
 pub fn overlap_coefficient(xset: set.Set(a), yset: set.Set(a)) -> Float {
-  let intersection: Float =
+  let intersection =
     set.intersection(xset, yset)
     |> set.size()
     |> conversion.int_to_float()
-  let minsize: Float =
+  let minsize =
     piecewise.minimum(set.size(xset), set.size(yset), int.compare)
     |> conversion.int_to_float()
   intersection /. minsize
@@ -1039,36 +1033,34 @@ pub fn cosine_similarity(
       msg
       |> Error
     Ok(_) -> {
-      let zipped_arr: List(#(Float, Float)) = list.zip(xarr, yarr)
+      let zipped_arr = list.zip(xarr, yarr)
 
-      let numerator_elements: List(Float) =
+      let numerator_elements =
         zipped_arr
-        |> list.map(fn(tuple: #(Float, Float)) -> Float {
-          pair.first(tuple) *. pair.second(tuple)
-        })
+        |> list.map(fn(tuple) { pair.first(tuple) *. pair.second(tuple) })
 
       case weights {
         option.None -> {
-          let numerator: Float =
+          let numerator =
             numerator_elements
             |> arithmetics.float_sum(option.None)
 
           let assert Ok(xarr_norm) = norm(xarr, 2.0, option.None)
           let assert Ok(yarr_norm) = norm(yarr, 2.0, option.None)
-          let denominator: Float = {
+          let denominator = {
             xarr_norm *. yarr_norm
           }
           numerator /. denominator
           |> Ok
         }
         _ -> {
-          let numerator: Float =
+          let numerator =
             numerator_elements
             |> arithmetics.float_sum(weights)
 
           let assert Ok(xarr_norm) = norm(xarr, 2.0, weights)
           let assert Ok(yarr_norm) = norm(yarr, 2.0, weights)
-          let denominator: Float = {
+          let denominator = {
             xarr_norm *. yarr_norm
           }
           numerator /. denominator
@@ -1137,7 +1129,7 @@ pub fn canberra_distance(
       msg
       |> Error
     Ok(_) -> {
-      let arr: List(Float) =
+      let arr =
         list.zip(xarr, yarr)
         |> list.map(canberra_distance_helper)
 
@@ -1158,9 +1150,9 @@ pub fn canberra_distance(
 }
 
 fn canberra_distance_helper(tuple: #(Float, Float)) -> Float {
-  let numerator: Float =
+  let numerator =
     piecewise.float_absolute_value({ pair.first(tuple) -. pair.second(tuple) })
-  let denominator: Float = {
+  let denominator = {
     piecewise.float_absolute_value(pair.first(tuple))
     +. piecewise.float_absolute_value(pair.second(tuple))
   }
@@ -1230,17 +1222,17 @@ pub fn braycurtis_distance(
       msg
       |> Error
     Ok(_) -> {
-      let zipped_arr: List(#(Float, Float)) = list.zip(xarr, yarr)
-      let numerator_elements: List(Float) =
+      let zipped_arr = list.zip(xarr, yarr)
+      let numerator_elements =
         zipped_arr
-        |> list.map(fn(tuple: #(Float, Float)) -> Float {
+        |> list.map(fn(tuple) {
           piecewise.float_absolute_value({
             pair.first(tuple) -. pair.second(tuple)
           })
         })
-      let denominator_elements: List(Float) =
+      let denominator_elements =
         zipped_arr
-        |> list.map(fn(tuple: #(Float, Float)) -> Float {
+        |> list.map(fn(tuple) {
           piecewise.float_absolute_value({
             pair.first(tuple) +. pair.second(tuple)
           })
diff --git a/src/gleam_community/maths/piecewise.gleam b/src/gleam_community/maths/piecewise.gleam
index 6931f8a..cebdc38 100644
--- a/src/gleam_community/maths/piecewise.gleam
+++ b/src/gleam_community/maths/piecewise.gleam
@@ -424,9 +424,9 @@ fn do_round(p: Float, x: Float, mode: option.Option(RoundingMode)) -> Float {
 }
 
 fn round_to_nearest(p: Float, x: Float) -> Float {
-  let xabs: Float = float_absolute_value(x) *. p
-  let xabs_truncated: Float = truncate_float(xabs)
-  let remainder: Float = xabs -. xabs_truncated
+  let xabs = float_absolute_value(x) *. p
+  let xabs_truncated = truncate_float(xabs)
+  let remainder = xabs -. xabs_truncated
   case remainder {
     _ if remainder >. 0.5 -> float_sign(x) *. truncate_float(xabs +. 1.0) /. p
     _ if remainder == 0.5 -> {
@@ -441,8 +441,8 @@ fn round_to_nearest(p: Float, x: Float) -> Float {
 }
 
 fn round_ties_away(p: Float, x: Float) -> Float {
-  let xabs: Float = float_absolute_value(x) *. p
-  let remainder: Float = xabs -. truncate_float(xabs)
+  let xabs = float_absolute_value(x) *. p
+  let remainder = xabs -. truncate_float(xabs)
   case remainder {
     _ if remainder >=. 0.5 -> float_sign(x) *. truncate_float(xabs +. 1.0) /. p
     _ -> float_sign(x) *. truncate_float(xabs) /. p
@@ -450,9 +450,9 @@ fn round_ties_away(p: Float, x: Float) -> Float {
 }
 
 fn round_ties_up(p: Float, x: Float) -> Float {
-  let xabs: Float = float_absolute_value(x) *. p
-  let xabs_truncated: Float = truncate_float(xabs)
-  let remainder: Float = xabs -. xabs_truncated
+  let xabs = float_absolute_value(x) *. p
+  let xabs_truncated = truncate_float(xabs)
+  let remainder = xabs -. xabs_truncated
   case remainder {
     _ if remainder >=. 0.5 && x >=. 0.0 ->
       float_sign(x) *. truncate_float(xabs +. 1.0) /. p
@@ -823,7 +823,7 @@ pub fn int_flip_sign(x: Int) -> Int {
 ///     </a>
 /// </div>
 ///
-pub fn minimum(x: a, y: a, compare: fn(a, a) -> order.Order) -> a {
+pub fn minimum(x: a, y: a, compare: fn(a, a) -> order.Order) {
   case compare(x, y) {
     order.Lt -> x
     order.Eq -> x
@@ -869,7 +869,7 @@ pub fn minimum(x: a, y: a, compare: fn(a, a) -> order.Order) -> a {
 ///     </a>
 /// </div>
 ///
-pub fn maximum(x: a, y: a, compare: fn(a, a) -> order.Order) -> a {
+pub fn maximum(x: a, y: a, compare: fn(a, a) -> order.Order) {
   case compare(x, y) {
     order.Lt -> y
     order.Eq -> y
@@ -909,7 +909,7 @@ pub fn maximum(x: a, y: a, compare: fn(a, a) -> order.Order) -> a {
 ///     </a>
 /// </div>
 ///
-pub fn minmax(x: a, y: a, compare: fn(a, a) -> order.Order) -> #(a, a) {
+pub fn minmax(x: a, y: a, compare: fn(a, a) -> order.Order) {
   #(minimum(x, y, compare), maximum(x, y, compare))
 }
 
@@ -954,7 +954,7 @@ pub fn list_minimum(
     [] -> Error(Nil)
     [x, ..rest] ->
       Ok(
-        list.fold(rest, x, fn(acc: a, element: a) {
+        list.fold(rest, x, fn(acc, element) {
           case compare(element, acc) {
             order.Lt -> element
             _ -> acc
@@ -1006,7 +1006,7 @@ pub fn list_maximum(
     [] -> Error(Nil)
     [x, ..rest] ->
       Ok(
-        list.fold(rest, x, fn(acc: a, element: a) {
+        list.fold(rest, x, fn(acc, element) {
           case compare(acc, element) {
             order.Lt -> element
             _ -> acc
@@ -1067,13 +1067,13 @@ pub fn arg_minimum(
         arr
         |> list_minimum(compare)
       arr
-      |> list.index_map(fn(element: a, index: Int) -> Int {
+      |> list.index_map(fn(element, index) {
         case compare(element, min) {
           order.Eq -> index
           _ -> -1
         }
       })
-      |> list.filter(fn(index: Int) -> Bool {
+      |> list.filter(fn(index) {
         case index {
           -1 -> False
           _ -> True
@@ -1135,13 +1135,13 @@ pub fn arg_maximum(
         arr
         |> list_maximum(compare)
       arr
-      |> list.index_map(fn(element: a, index: Int) -> Int {
+      |> list.index_map(fn(element, index) {
         case compare(element, max) {
           order.Eq -> index
           _ -> -1
         }
       })
-      |> list.filter(fn(index: Int) -> Bool {
+      |> list.filter(fn(index) {
         case index {
           -1 -> False
           _ -> True
@@ -1200,9 +1200,9 @@ pub fn extrema(
     [] -> Error(Nil)
     [x, ..rest] ->
       Ok(
-        list.fold(rest, #(x, x), fn(acc: #(a, a), element: a) {
-          let first: a = pair.first(acc)
-          let second: a = pair.second(acc)
+        list.fold(rest, #(x, x), fn(acc, element) {
+          let first = pair.first(acc)
+          let second = pair.second(acc)
           case compare(element, first), compare(second, element) {
             order.Lt, order.Lt -> #(element, element)
             order.Lt, _ -> #(element, second)
diff --git a/src/gleam_community/maths/predicates.gleam b/src/gleam_community/maths/predicates.gleam
index 37391e9..73e5743 100644
--- a/src/gleam_community/maths/predicates.gleam
+++ b/src/gleam_community/maths/predicates.gleam
@@ -71,12 +71,12 @@ import gleam_community/maths/piecewise
 ///     import gleam_community/maths/predicates
 ///
 ///     pub fn example () {
-///       let val: Float = 99.
-///       let ref_val: Float = 100.
+///       let val = 99.
+///       let ref_val = 100.
 ///       // We set 'atol' and 'rtol' such that the values are equivalent
 ///       // if 'val' is within 1 percent of 'ref_val' +/- 0.1
-///       let rtol: Float = 0.01
-///       let atol: Float = 0.10
+///       let rtol = 0.01
+///       let atol = 0.10
 ///       floatx.is_close(val, ref_val, rtol, atol)
 ///       |> should.be_true()
 ///     }
@@ -89,8 +89,8 @@ import gleam_community/maths/piecewise
 /// </div>
 ///
 pub fn is_close(a: Float, b: Float, rtol: Float, atol: Float) -> Bool {
-  let x: Float = float_absolute_difference(a, b)
-  let y: Float = atol +. rtol *. float_absolute_value(b)
+  let x = float_absolute_difference(a, b)
+  let y = atol +. rtol *. float_absolute_value(b)
   case x <=. y {
     True -> True
     False -> False
@@ -126,20 +126,20 @@ fn float_absolute_difference(a: Float, b: Float) -> Float {
 ///     import gleam_community/maths/predicates
 ///
 ///     pub fn example () {
-///       let val: Float = 99.
-///       let ref_val: Float = 100.
-///       let xarr: List(Float) = list.repeat(val, 42)
-///       let yarr: List(Float) = list.repeat(ref_val, 42)
+///       let val = 99.
+///       let ref_val = 100.
+///       let xarr = list.repeat(val, 42)
+///       let yarr = list.repeat(ref_val, 42)
 ///       // We set 'atol' and 'rtol' such that the values are equivalent
 ///       // if 'val' is within 1 percent of 'ref_val' +/- 0.1
-///       let rtol: Float = 0.01
-///       let atol: Float = 0.10
+///       let rtol = 0.01
+///       let atol = 0.10
 ///       predicates.all_close(xarr, yarr, rtol, atol)
 ///       |> fn(zarr: Result(List(Bool), Nil)) -> Result(Bool, Nil) {
 ///         case zarr {
 ///           Ok(arr) ->
 ///             arr
-///             |> list.all(fn(a: Bool) -> Bool { a })
+///             |> list.all(fn(a) { a })
 ///             |> Ok
 ///           _ -> Nil |> Error
 ///         }
@@ -160,15 +160,13 @@ pub fn all_close(
   rtol: Float,
   atol: Float,
 ) -> Result(List(Bool), Nil) {
-  let xlen: Int = list.length(xarr)
-  let ylen: Int = list.length(yarr)
+  let xlen = list.length(xarr)
+  let ylen = list.length(yarr)
   case xlen == ylen {
     False -> Error(Nil)
     True ->
       list.zip(xarr, yarr)
-      |> list.map(fn(z: #(Float, Float)) -> Bool {
-        is_close(pair.first(z), pair.second(z), rtol, atol)
-      })
+      |> list.map(fn(z) { is_close(pair.first(z), pair.second(z), rtol, atol) })
       |> Ok
   }
 }
@@ -302,7 +300,7 @@ fn do_sum(arr: List(Int)) -> Int {
     [] -> 0
     _ ->
       arr
-      |> list.fold(0, fn(acc: Int, a: Int) -> Int { a + acc })
+      |> list.fold(0, fn(acc, a) { a + acc })
   }
 }
 
@@ -444,7 +442,7 @@ fn miller_rabin_test(n: Int, k: Int) -> Bool {
     _, 0 -> True
     _, _ -> {
       // Generate a random int in the range [2, n]
-      let random_candidate: Int = 2 + int.random(n - 2)
+      let random_candidate = 2 + int.random(n - 2)
       case powmod_with_check(random_candidate, n - 1, n) == 1 {
         True -> miller_rabin_test(n, k - 1)
         False -> False
@@ -457,7 +455,7 @@ fn powmod_with_check(base: Int, exponent: Int, modulus: Int) -> Int {
   case exponent, { exponent % 2 } == 0 {
     0, _ -> 1
     _, True -> {
-      let x: Int = powmod_with_check(base, exponent / 2, modulus)
+      let x = powmod_with_check(base, exponent / 2, modulus)
       case { x * x } % modulus, x != 1 && x != { modulus - 1 } {
         1, True -> 0
         _, _ -> { x * x } % modulus
diff --git a/src/gleam_community/maths/sequences.gleam b/src/gleam_community/maths/sequences.gleam
index daff369..c801184 100644
--- a/src/gleam_community/maths/sequences.gleam
+++ b/src/gleam_community/maths/sequences.gleam
@@ -102,7 +102,7 @@ pub fn arange(
         |> conversion.float_to_int()
 
       iterator.range(0, num - 1)
-      |> iterator.map(fn(i: Int) {
+      |> iterator.map(fn(i) {
         start +. conversion.int_to_float(i) *. step_abs *. direction
       })
     }
@@ -161,7 +161,7 @@ pub fn linear_space(
   num: Int,
   endpoint: Bool,
 ) -> Result(iterator.Iterator(Float), Nil) {
-  let direction: Float = case start <=. stop {
+  let direction = case start <=. stop {
     True -> 1.0
     False -> -1.0
   }
@@ -179,7 +179,7 @@ pub fn linear_space(
   case num > 0 {
     True -> {
       iterator.range(0, num - 1)
-      |> iterator.map(fn(i: Int) -> Float {
+      |> iterator.map(fn(i) {
         start +. conversion.int_to_float(i) *. increment *. direction
       })
       |> Ok
@@ -244,7 +244,7 @@ pub fn logarithmic_space(
     True -> {
       let assert Ok(linspace) = linear_space(start, stop, num, endpoint)
       linspace
-      |> iterator.map(fn(i: Float) -> Float {
+      |> iterator.map(fn(i) {
         let assert Ok(result) = elementary.power(base, i)
         result
       })
diff --git a/src/gleam_community/maths/special.gleam b/src/gleam_community/maths/special.gleam
index ae5c8f6..6422709 100644
--- a/src/gleam_community/maths/special.gleam
+++ b/src/gleam_community/maths/special.gleam
@@ -76,17 +76,17 @@ pub fn beta(x: Float, y: Float) -> Float {
 /// </div>
 ///
 pub fn erf(x: Float) -> Float {
-  let assert [a1, a2, a3, a4, a5]: List(Float) = [
+  let assert [a1, a2, a3, a4, a5] = [
     0.254829592, -0.284496736, 1.421413741, -1.453152027, 1.061405429,
   ]
-  let p: Float = 0.3275911
+  let p = 0.3275911
 
-  let sign: Float = piecewise.float_sign(x)
-  let x: Float = piecewise.float_absolute_value(x)
+  let sign = piecewise.float_sign(x)
+  let x = piecewise.float_absolute_value(x)
 
   // Formula 7.1.26 given in Abramowitz and Stegun.
-  let t: Float = 1.0 /. { 1.0 +. p *. x }
-  let y: Float =
+  let t = 1.0 /. { 1.0 +. p *. x }
+  let y =
     1.0
     -. { { { { a5 *. t +. a4 } *. t +. a3 } *. t +. a2 } *. t +. a1 }
     *. t
@@ -131,14 +131,14 @@ fn gamma_lanczos(x: Float) -> Float {
       /. { elementary.sin(elementary.pi() *. x) *. gamma_lanczos(1.0 -. x) }
     False -> {
       let z = x -. 1.0
-      let x: Float =
-        list.index_fold(lanczos_p, 0.0, fn(acc: Float, v: Float, index: Int) {
+      let x =
+        list.index_fold(lanczos_p, 0.0, fn(acc, v, index) {
           case index > 0 {
             True -> acc +. v /. { z +. conversion.int_to_float(index) }
             False -> v
           }
         })
-      let t: Float = z +. lanczos_g +. 0.5
+      let t = z +. lanczos_g +. 0.5
       let assert Ok(v1) = elementary.power(2.0 *. elementary.pi(), 0.5)
       let assert Ok(v2) = elementary.power(t, z +. 0.5)
       v1 *. v2 *. elementary.exponential(-1.0 *. t) *. x
@@ -187,8 +187,8 @@ fn incomplete_gamma_sum(
   case t {
     0.0 -> s
     _ -> {
-      let ns: Float = s +. t
-      let nt: Float = t *. { x /. { a +. n } }
+      let ns = s +. t
+      let nt = t *. { x /. { a +. n } }
       incomplete_gamma_sum(a, x, nt, ns, n +. 1.0)
     }
   }
diff --git a/test/gleam_community/maths/combinatorics_test.gleam b/test/gleam_community/maths/combinatorics_test.gleam
index 087122f..729f450 100644
--- a/test/gleam_community/maths/combinatorics_test.gleam
+++ b/test/gleam_community/maths/combinatorics_test.gleam
@@ -72,7 +72,7 @@ pub fn int_combination_test() {
 
   combinatorics.combination(7, 5, option.Some(combinatorics.WithRepetitions))
   |> should.equal(Ok(462))
-  // NOTE: Tests with the 'combination' function that produce values that exceed 
+  // NOTE: Tests with the 'combination' function that produce values that exceed
   // precision of the JavaScript 'Number' primitive will result in errors
 }
 
@@ -697,4 +697,11 @@ pub fn example_test() {
   |> should.equal(
     set.from_list([#(1.0, 1.0), #(1.0, 2.0), #(10.0, 1.0), #(10.0, 2.0)]),
   )
+
+  // Cartesian product of two sets with different types
+  set.from_list(["1", "10"])
+  |> combinatorics.cartesian_product(set.from_list([1.0, 2.0]))
+  |> should.equal(
+    set.from_list([#("1", 1.0), #("1", 2.0), #("10", 1.0), #("10", 2.0)]),
+  )
 }
diff --git a/test/gleam_community/maths/metrics_test.gleam b/test/gleam_community/maths/metrics_test.gleam
index dcf43eb..4debea5 100644
--- a/test/gleam_community/maths/metrics_test.gleam
+++ b/test/gleam_community/maths/metrics_test.gleam
@@ -317,7 +317,7 @@ pub fn median_test() {
 
 pub fn variance_test() {
   // Degrees of freedom
-  let ddof: Int = 1
+  let ddof = 1
 
   // An empty list returns an error
   []
@@ -332,7 +332,7 @@ pub fn variance_test() {
 
 pub fn standard_deviation_test() {
   // Degrees of freedom
-  let ddof: Int = 1
+  let ddof = 1
 
   // An empty list returns an error
   []
@@ -349,19 +349,18 @@ pub fn jaccard_index_test() {
   metrics.jaccard_index(set.from_list([]), set.from_list([]))
   |> should.equal(0.0)
 
-  let set_a: set.Set(Int) = set.from_list([0, 1, 2, 5, 6, 8, 9])
-  let set_b: set.Set(Int) = set.from_list([0, 2, 3, 4, 5, 7, 9])
+  let set_a = set.from_list([0, 1, 2, 5, 6, 8, 9])
+  let set_b = set.from_list([0, 2, 3, 4, 5, 7, 9])
   metrics.jaccard_index(set_a, set_b)
   |> should.equal(4.0 /. 10.0)
 
-  let set_c: set.Set(Int) = set.from_list([0, 1, 2, 3, 4, 5])
-  let set_d: set.Set(Int) = set.from_list([6, 7, 8, 9, 10])
+  let set_c = set.from_list([0, 1, 2, 3, 4, 5])
+  let set_d = set.from_list([6, 7, 8, 9, 10])
   metrics.jaccard_index(set_c, set_d)
   |> should.equal(0.0 /. 11.0)
 
-  let set_e: set.Set(String) = set.from_list(["cat", "dog", "hippo", "monkey"])
-  let set_f: set.Set(String) =
-    set.from_list(["monkey", "rhino", "ostrich", "salmon"])
+  let set_e = set.from_list(["cat", "dog", "hippo", "monkey"])
+  let set_f = set.from_list(["monkey", "rhino", "ostrich", "salmon"])
   metrics.jaccard_index(set_e, set_f)
   |> should.equal(1.0 /. 7.0)
 }
@@ -370,19 +369,18 @@ pub fn sorensen_dice_coefficient_test() {
   metrics.sorensen_dice_coefficient(set.from_list([]), set.from_list([]))
   |> should.equal(0.0)
 
-  let set_a: set.Set(Int) = set.from_list([0, 1, 2, 5, 6, 8, 9])
-  let set_b: set.Set(Int) = set.from_list([0, 2, 3, 4, 5, 7, 9])
+  let set_a = set.from_list([0, 1, 2, 5, 6, 8, 9])
+  let set_b = set.from_list([0, 2, 3, 4, 5, 7, 9])
   metrics.sorensen_dice_coefficient(set_a, set_b)
   |> should.equal(2.0 *. 4.0 /. { 7.0 +. 7.0 })
 
-  let set_c: set.Set(Int) = set.from_list([0, 1, 2, 3, 4, 5])
-  let set_d: set.Set(Int) = set.from_list([6, 7, 8, 9, 10])
+  let set_c = set.from_list([0, 1, 2, 3, 4, 5])
+  let set_d = set.from_list([6, 7, 8, 9, 10])
   metrics.sorensen_dice_coefficient(set_c, set_d)
   |> should.equal(2.0 *. 0.0 /. { 6.0 +. 5.0 })
 
-  let set_e: set.Set(String) = set.from_list(["cat", "dog", "hippo", "monkey"])
-  let set_f: set.Set(String) =
-    set.from_list(["monkey", "rhino", "ostrich", "salmon", "spider"])
+  let set_e = set.from_list(["cat", "dog", "hippo", "monkey"])
+  let set_f = set.from_list(["monkey", "rhino", "ostrich", "salmon", "spider"])
   metrics.sorensen_dice_coefficient(set_e, set_f)
   |> should.equal(2.0 *. 1.0 /. { 4.0 +. 5.0 })
 }
@@ -391,20 +389,18 @@ pub fn overlap_coefficient_test() {
   metrics.overlap_coefficient(set.from_list([]), set.from_list([]))
   |> should.equal(0.0)
 
-  let set_a: set.Set(Int) = set.from_list([0, 1, 2, 5, 6, 8, 9])
-  let set_b: set.Set(Int) = set.from_list([0, 2, 3, 4, 5, 7, 9])
+  let set_a = set.from_list([0, 1, 2, 5, 6, 8, 9])
+  let set_b = set.from_list([0, 2, 3, 4, 5, 7, 9])
   metrics.overlap_coefficient(set_a, set_b)
   |> should.equal(4.0 /. 7.0)
 
-  let set_c: set.Set(Int) = set.from_list([0, 1, 2, 3, 4, 5])
-  let set_d: set.Set(Int) = set.from_list([6, 7, 8, 9, 10])
+  let set_c = set.from_list([0, 1, 2, 3, 4, 5])
+  let set_d = set.from_list([6, 7, 8, 9, 10])
   metrics.overlap_coefficient(set_c, set_d)
   |> should.equal(0.0 /. 5.0)
 
-  let set_e: set.Set(String) =
-    set.from_list(["horse", "dog", "hippo", "monkey", "bird"])
-  let set_f: set.Set(String) =
-    set.from_list(["monkey", "bird", "ostrich", "salmon"])
+  let set_e = set.from_list(["horse", "dog", "hippo", "monkey", "bird"])
+  let set_f = set.from_list(["monkey", "bird", "ostrich", "salmon"])
   metrics.overlap_coefficient(set_e, set_f)
   |> should.equal(2.0 /. 4.0)
 }
@@ -440,7 +436,7 @@ pub fn cosine_similarity_test() {
   metrics.cosine_similarity([-1.0, -2.0, -3.0], [1.0, 2.0, 3.0], option.None)
   |> should.equal(Ok(-1.0))
 
-  // Try with arbitrary valid input 
+  // Try with arbitrary valid input
   let assert Ok(result) =
     metrics.cosine_similarity([1.0, 2.0, 3.0], [4.0, 5.0, 6.0], option.None)
   result
diff --git a/test/gleam_community/maths/predicates_test.gleam b/test/gleam_community/maths/predicates_test.gleam
index 955e46e..e544eb5 100644
--- a/test/gleam_community/maths/predicates_test.gleam
+++ b/test/gleam_community/maths/predicates_test.gleam
@@ -3,31 +3,31 @@ import gleam_community/maths/predicates
 import gleeunit/should
 
 pub fn float_is_close_test() {
-  let val: Float = 99.0
-  let ref_val: Float = 100.0
+  let val = 99.0
+  let ref_val = 100.0
   // We set 'atol' and 'rtol' such that the values are equivalent
   // if 'val' is within 1 percent of 'ref_val' +/- 0.1
-  let rtol: Float = 0.01
-  let atol: Float = 0.1
+  let rtol = 0.01
+  let atol = 0.1
   predicates.is_close(val, ref_val, rtol, atol)
   |> should.be_true()
 }
 
 pub fn float_list_all_close_test() {
-  let val: Float = 99.0
-  let ref_val: Float = 100.0
-  let xarr: List(Float) = list.repeat(val, 42)
-  let yarr: List(Float) = list.repeat(ref_val, 42)
+  let val = 99.0
+  let ref_val = 100.0
+  let xarr = list.repeat(val, 42)
+  let yarr = list.repeat(ref_val, 42)
   // We set 'atol' and 'rtol' such that the values are equivalent
   // if 'val' is within 1 percent of 'ref_val' +/- 0.1
-  let rtol: Float = 0.01
-  let atol: Float = 0.1
+  let rtol = 0.01
+  let atol = 0.1
   predicates.all_close(xarr, yarr, rtol, atol)
   |> fn(zarr: Result(List(Bool), Nil)) -> Result(Bool, Nil) {
     case zarr {
       Ok(arr) ->
         arr
-        |> list.all(fn(a: Bool) -> Bool { a })
+        |> list.all(fn(a) { a })
         |> Ok
       _ ->
         Nil