XLISP 3.3, September 6, 2002 Copyright (c) 1984-2002, by David Betz
[1] ((lambda () (+ "one" "two")))

Error: incorrect type - "one"
happened in: #<Code #x0x7f64bfbb4f68>
Entering break loop ('(reset)' to quit)
Debug 1> [1] (reset)

[1] ((named-lambda b () (+ "one" "two")))

Error: incorrect type - "one"
happened in: #<Code B>
Entering break loop ('(reset)' to quit)
Debug 1> [1] (reset)

[1]

(((lambda (f)
    ((lambda (proc)
       (f (lambda (arg) ((proc proc) arg))))
     (lambda (proc)
       (f (lambda (arg) ((proc proc) arg))))))
  (lambda (self)
    (lambda (ls)
      (if (null? ls) 0 (+ 1 (self (cdr ls)))))))
 '(a b c d e))

[1] (named-lambda a () a)

#<Procedure A>
[2] ((named-lambda a () a))

error: unbound variable - a
happened in: #<Code A>
Entering break loop ('(reset)' to quit)
Debug 1> [2]