These are the functions for RingElem input.
Let in be a string or stream (e.g. reading from file),
and R any ring.
They both return the expression read from in and evaluated in
R.
ReadExpr(R, in) -- keeps reading to the end of input (so it's
convenient for reading from a string)
ReadExprSemicolon(R, in) -- stops at the semicolon (convenient for reading from file or standard input)
Recognized operations are
+ - * / ^ ()
Code is so nice it does not need any documentation! ;-)
2014