An interesting historical note, but it says nothing about the relative 'primitiveness' of COND vs IF. It's not uncommon at all in mathematics to build a system

An interesting historical note, but it says nothing about the relative 'primitiveness' of COND vs IF. It's not uncommon at all in mathematics to build a system with certain axioms, and then improve them later, when it's realized that simpler axioms can be used to build more complex constructs.