>>24
notation gets pushed on the stack.
postfix ( not -- postnot ) transforms a notation on the stack to postfix-notation.
using ( obj -- using<obj> ) marks the first object on the stack as being used.
? ( obj -- obj? ) marks the first object on the stack as a question.
you gets pushed on the stack.
are ( what subject -- simple-sentence ) takes the first two object on the stack, and combines them to form a simple sentence.