Major Section: HISTORY
Examples:
:pl2 (+ x y) nil ; prints rules that apply to (+ x y)
:pl2 (+ x y) foo ; prints rules named foo that apply to (+ x y)
:pl2 (+ x y) (:rewrite foo) ; if the rule with rune (:rewrite foo) applies
; to (+ x y), then print it
:pl2 (+ x y) (:type-prescription foo)
; as above, but for the indicated
; type-prescription rule
Pl2 takes two arguments. The first is a term. The second is either
nil or a ``rule-id'' that is either a symbol or a rune. The result
is to print rules of class :rewrite, :definition,
:meta, :linear, and :type-prescription that apply to
the given term. Indeed, :pl2 prints exactly what is printed by applying
:pl to the first argument -- see pl -- except that if the
second argument is not nil then it is used to filter the rules printed,
as follows.
If the rule-id is a symbol, then only rules whose name is that symbol will be printed.
If the rule-id is a rune, then at most one rule will be printed: the rule named by that rune (if the rule would be printed by
:pl).
