'********** inference on tense 'If someone hold key_101, he will enter room_101 (in 100 steps) <(&/,<(*, $x, key_101) --> hold>,+100) =/> <(*, $x, room_101) --> enter>>. 'John is entering room_101 now <(*,John,room_101) --> enter>. :|: 15 'John held the key_101 (105 steps before) ''outputMustContain('<(*,John,key_101) --> hold>. :!-105: %1.00;0.45%')