I presume they are placeholders to represent any binary operator, i.e. +, -, etc...

stygiansonic on Dec 31, 2016 | parent | context | favorite | on: Questions about Superoptimization

I presume they are placeholders to represent any binary operator, i.e. +, -, etc. The operator should be the same in all the placeholders or have the same precedence for the two expressions to be equivalent.