Code-golf centered improvements:
There are too many useless one-byte tokens. All those graphing commands, the two unused bytes, IS>, etc. Those could be taken up by lots of things:
Command for sub("SOMESTRING",X,1, in the form of char(X,"SOMESTRING
Command for seq(inString("OTHERSTRING",sub(Ans,X,1)),X,1,length(Ans, in the format of charPosIn("OTHERSTRING",Ans
Support for empty lists, where the deltalist( of a one-element list would return one
Sign function, to replace tanh(E9X
cumProd( to complement cumSum(
Generally more powerful list operations, maybe not at the level of languages like APL, but maybe one level of nested lists, with the associated commands, and filling lists with zeroes rather than erroring when they are added to lists of different dimensions.
Finally, Ans is used more than sixteen times as much as the least-used tokens. Therefore, it should take up all of 0xF0 to 0xFF, and be only half a byte long. Impractical? Very. Reduces code size? Slightly.