Arguments

This function may not behave as expected. Internally, all the expressions are implemented as combinations of elementary operations. Thus, the operation 'sum' has two arguments. For instance, summing a plus b has two arguments (a and b), but s i n left parenthesis x right parenthesis plus y asterisk times z has also two arguments: s i n left parenthesis x right parenthesis and y asterisk times z.

arguments(Expression)

Given an expression, returns the arguments of the main operation.