Provide mathematical functions on floating-point numbers. This is a sub-signature of REAL.
signature MATH = sig type real val acos : real -> real val asin : real -> real val atan : real -> real val atan2 : real * real -> real val cos : real -> real val cosh : real -> real val e : real val exp : real -> real val ln : real -> real val log10 : real -> real val pi : real val pow : real * real -> real val sin : real -> real val sinh : real -> real val sqrt : real -> real val tan : real -> real val tanh : real -> real end