Algol based languages -> 1st order logic (implicit 'single' return) algol languages array/stack with 'struct' abstract ('struc' abstract converted by compiler

Algol based languages -> 1st order logic (implicit 'single' return) algol languages array/stack with 'struct' abstract ('struc' abstract converted by compiler to ether parallel array(s) and/or array byte grouping per array ordinal index offset) Lisp languages -> 2nd order logic (implicit nil/1 or many returns) lisp is a tree / heap language where tree node is the 'implied' struct. tree/heap much more flexible than fixed size array of strucs.