jkr2255 / prop_logic

    class << self

      def call(term)

        # obvious value

        return True if term == True

        variables = term.variables

        PropLogic.all_combination(variables) do |trues|

          falses = variables - trues

          next unless term.assign(trues, falses).reduce == True

          # SAT

          negated_falses = falses.map(&:not)

          return PropLogic.all_and(*trues, *negated_falses)

        end

        # UNSAT

        false