Speedup Automake::DisjConditions::invert(). * lib/Automake/Condition.pm (multiply): New. * lib/Automake/DisjConditions.pm (_multiply): Use it. (sub_conditions): Likewise. * lib/Automake/Condition.pm (reduce): Rename to ... (reduce_and): ... this. (reduce_or): New. * lib/Automake/DisjConditions.pm (_multiply): Use reduce_or(). * lib/Automake/tests/Condition.pl (test_reduce): Rename to ... (test_reduce_and): ... this. (test_reduce_or): New. * lib/Automake/tests/DisjConditions.pl (test_invert): Update to reflect effect of reduce_or(). (test_simplify): Don't skip invert() on larger inputs.