We could start with a mininal version of such library and then we could extend it with other functions. Some of the most important ones could be the following:

Rounding

• ceil(x: Num): Num - rounds up to the nearest integer
• floor(x: Num): Num - rounds down to the nearest
• round(x: Num): Num - rounds to the nearest integer

Absolute and sign

• abs(x: Num): Num - absolute value
• sign(x: Num): Num - sign function, returns -1, 0, or 1 depending on the sign of x

Min / Max

• min(a: Num, b: Num): Num
• max(a: Num, b: Num): Num

Optional: Power, root, exponential, logarithms and trigonometric

These can be easily evaluated using bc with flag -l

• pow(base: Num, exponent: Num): Num - power function
• sqrt(x: Num): Num - square root
• exp(x: Num): Num - exponential function
• log(x: Num): Num - natural logarithm
• log10(x: Num): Num - base-10 logarithm
• sin(x: Num): Num - sine
• cos(x: Num): Num - cosine
• tan(x: Num): Num - tangent