diff --git a/calc.py b/calc.py
deleted file mode 100644
index 242e6604b..000000000
--- a/calc.py
+++ /dev/null
@@ -1,3 +0,0 @@
-DEFAULT_PRIME = 2**251 + 17 * 2**192 + 1
-
-print((pow(3, DEFAULT_PRIME-2, DEFAULT_PRIME)))
\ No newline at end of file
diff --git a/src/common.cairo b/src/common.cairo
index 0e28c54fc..cf165c02e 100644
--- a/src/common.cairo
+++ b/src/common.cairo
@@ -6,6 +6,7 @@ mod array_append;
 mod math;
 mod array_print;
 mod array_extend;
+mod consts;
 
 #[cfg(test)]
 mod tests;
diff --git a/src/common/array_extend.cairo b/src/common/array_extend.cairo
index d8cc703c6..08fbe6607 100644
--- a/src/common/array_extend.cairo
+++ b/src/common/array_extend.cairo
@@ -1,7 +1,4 @@
-trait ArrayExtendTrait<T> {
-    fn extend(ref self: Array<T>, span: Span<T>);
-}
-
+#[generate_trait]
 impl ArrayExtend<T, +Copy<T>, +Drop<T>> of ArrayExtendTrait<T> {
     fn extend(ref self: Array<T>, span: Span<T>) {
         let mut i = 0;
diff --git a/src/common/consts.cairo b/src/common/consts.cairo
new file mode 100644
index 000000000..195fba4cd
--- /dev/null
+++ b/src/common/consts.cairo
@@ -0,0 +1,2 @@
+const STARK_PRIME_MINUS_TWO: felt252 =
+    3618502788666131213697322783095070105623107215331596699973092056135872020479;
diff --git a/src/common/math.cairo b/src/common/math.cairo
index a7725c167..978aacc95 100644
--- a/src/common/math.cairo
+++ b/src/common/math.cairo
@@ -1,3 +1,5 @@
+use cairo_verifier::common::consts::STARK_PRIME_MINUS_TWO;
+
 fn pow(base: felt252, exp: felt252) -> felt252 {
     if exp == 0 {
         return 1;
@@ -23,5 +25,5 @@ fn pow(base: felt252, exp: felt252) -> felt252 {
 fn mul_inverse(x: felt252) -> felt252 {
     // From Fermat's little theorem, a ^ (p - 1) = 1 when p is prime and a != 0. Since a ^ (p - 1) = a · a ^ (p - 2) we have that 
     // a ^ (p - 2) is the multiplicative inverse of a modulo p.
-    pow(x, 3618502788666131213697322783095070105623107215331596699973092056135872020479)
+    pow(x, STARK_PRIME_MINUS_TWO)
 }
diff --git a/src/fri/fri_config.cairo b/src/fri/fri_config.cairo
index 63fb9d379..02ff63a0c 100644
--- a/src/fri/fri_config.cairo
+++ b/src/fri/fri_config.cairo
@@ -27,10 +27,9 @@ struct FriConfig {
 fn fri_config_validate(
     config: FriConfig, log_n_cosets: felt252, n_verifier_friendly_commitment_layers: felt252
 ) -> felt252 {
-    let n_layers = config.n_layers.try_into().unwrap();
-    let log_last_layer_degree_bound = config.log_last_layer_degree_bound.try_into().unwrap();
+    let n_layers: u32 = config.n_layers.try_into().unwrap();
+    let log_last_layer_degree_bound: u32 = config.log_last_layer_degree_bound.try_into().unwrap();
 
-    assert(log_last_layer_degree_bound >= 0, 'Must be non negative value');
     assert(log_last_layer_degree_bound <= MAX_LAST_LAYER_LOG_DEGREE_BOUND, 'Value too big');
 
     assert(*config.fri_step_sizes.at(0) == 0, 'Invalid value');
diff --git a/src/fri/fri_layer.cairo b/src/fri/fri_layer.cairo
index 2136b27de..74842a20e 100644
--- a/src/fri/fri_layer.cairo
+++ b/src/fri/fri_layer.cairo
@@ -101,7 +101,6 @@ fn compute_next_layer(
         let coset_size_u256: u256 = coset_size.into();
 
         let coset_index = (index_u256 / coset_size_u256).low.into();
-        assert(coset_index.into() >= 0_u256, 'Must be non negative value');
 
         verify_indices.append(coset_index);
 
@@ -116,7 +115,7 @@ fn compute_next_layer(
 
         // Verify that at least one query was consumed.
         let coset_elements_len = coset_elements.len();
-        assert(coset_elements_len >= 0, 'Must be non negative value');
+        assert(coset_elements_len > 0, 'Must be non negative value');
 
         let coset_elements_span = coset_elements.span();