Allowed mathematical operators

The following Maple mathematical operators are recognized in an expression:

• arithmetic: +,-,*,/,$\hat{ }$,**
• trigonometry: sin,cos,tan,cot,sec,csc,arcsin,arccos,arctan,arccot
• hyperbolic trigonometry : sinh,cosh,tanh,coth,sech,csch,arcsinh,arccosh,arctanh,arccoth
• log and exponential: log,ln,log10,exp
• miscellaneous: abs, signum, signum(1,..),abs(1,...),INTERVAL,ceil,floor,round

Note that the value of signum(x)=|x|/x where x is an interval whose absolute value is lower than
`ALIAS/value_sign_signum` is set to the Maple variable _Envsignum0. This allows one to specify the value of signum(0).