Supported functions include all elements of the S3 Math
group excluding the "cumulative" ones, which are not supported at
this time and will raise an error. As of this writing, functions
supported include (from R help) abs, sign, sqrt, floor,
ceiling, trunc, round, signif, exp, log, expm1,
log1p, cos, sin, tan, cospi, sinpi, tanpi, acos,
asin, atan, cosh, sinh, tanh, acosh, asinh,
atanh, lgamma, gamma, digamma, and trigamma.
Functions cumsum, cumprod, cummax, and cummin are not
supported at this time and will raise an error.