 )
-> foo
: (pp 'foo)                      # Pretty-print 'foo'
(de foo (N)
   (unless (>= 90 N 10)          # Assertion code exists
      (quit "'assert' failed" '(>= 90 N 10)) )
   (bar N) )
-> foo
: (foo 7)                        # Try it
(>= 90 N 10) -- Assertion failed
?

# Start in non-debug mode
$ pil
: (de foo (N)
   ~(assert (>= 90 N 10))
   (bar N) )
-> foo
: (pp 'foo)                      # Pretty-print 'foo'
(de foo (N)
   (bar N) )                     # Assertion code does not exist
-> foo
</pr