; Metacircular Evaluator II with Jay (the magician).
; 7B:(3m3s) Creeping Featurism
; 7B:(4m3s) Feeping Creaturism

; multiple arguments
;;; REDEFINE PAIR-UP
(DEFINE PAIR-UP
  (LAMBDA (VARS VALS)
    (COND
     ((EQ? VARS '())
      (COND ((EQ? VALS '()) '())
            (ELSE (ERROR THA))))
     ((SYMBOL? VARS)
      (CONS (CONS VARS VALS) '()))
     ((EQ? VALS '()) (ERROR TFA))
     (ELSE
      (CONS (CONS (CAR VARS)
                  (CAR VALS))
            (PAIR-UP (CDR VARS)
                     (CDR VALS)))))))
; QUESTIONS 7B:(15m50s) BREAK

; Jay tries hard again to simplify and unify his code-statements.
;  7B:(27m3s) Lexical (static) binding vs.
;             Dynamic binding "The fameous bug."
; QUESTION 7B:(37m50s) BREAK

; How to conditionally evaluate or delay. (Another try on
;  the promise-system)
; (define (unless p c a)
;   (cond ((not p) c)
;         (else a)))

; 7B:(56m31s) 'THUNK
; QUESTIONS, (END)