I call it the 'ideq' (pronounced eye-deck), a portmanteau of 'identity equals' because in my scheme background, equivalent (eqv?) is less strict than equal (eq?

I call it the 'ideq' (pronounced eye-deck), a portmanteau of 'identity equals' because in my scheme background, equivalent (eqv?) is less strict than equal (eq?). The 'identity' part of the name, in programming context, means the address of the item. So in order of strictness: equivalent < equal < ideq