'********** variables introduction 'Key-1 opens Lock-1. <{key1} --> (/,open,_,{lock1})>. 'Key-1 is a key. <{key1} --> key>. 45 'I guess every key can open Lock-1. ''outputMustContain('<<$1 --> key> ==> <$1 --> (/,open,_,{lock1})>>. %1.00;0.45%') 'Some key can open Lock-1. ''//outputMustContain('(&&,<#1 --> (/,open,_,{lock1})>,<#1 --> key>). %1.00;0.81%') //reversed '' outputMustContain('(&&,<#1 --> (/,open,_,{lock1})>,<#1 --> key>). %1.00;0.25%')