question about output

[AmosJoseph]

Multi-fidelity learning from the formulas

Pardon, what's the meaning of output below:
step Train loss Test loss Test metric
0 [4.02e+01, 5.22e+01, 1.95e+00] [8.21e+01, 2.41e+01, 1.95e+00] [1.00e+00, 1.04e+00]

There are 3 items for Train loss and Test loss. Why? 3 items are about high, low, and multi fidelity?

Test metric has 2 items? What are them?
The mean and standard deviation for the relative L2 errors?

sorry to bother！

[lululxvi]

• losses: low-fidelity loss, high-fidelity loss, regularization
• Test metric: l2 relative error for low- and high-fidelity prediction