I think your second point actually is covered: > Note that “applying” an operator can mean a couple of different things in this context. You could actually exe

I think your second point actually is covered: > Note that “applying” an operator can mean a couple of different things in this context. You could actually execute the operators, in which case the operands would be numerical values of all the terms and subexpressions; you could also build a syntax tree, in which case the operands would be subtrees. The algorithm works the same way in either case.