the_definitions : thm list ref
  # !the_definitions;;
  val it : thm list =
    [|- !(<<) p s t.
            superadmissible (<<) p s t <=>
            admissible (<<) (\f a. T) s p ==> tailadmissible (<<) p s t;
     ...
     ...
     |- (/\) = (\p q. (\f. f p q) = (\f. f T T)); |- T <=> (\p. p) = (\p. p)]
# new_definition `false <=> F`;; val it : thm = |- false <=> F
  # !the_definitions;;
  val it : thm list =
    [|- false <=> F;
     ...
     ...
     |- (/\) = (\p q. (\f. f p q) = (\f. f T T)); |- T <=> (\p. p) = (\p. p)]