'***** second level variable unification 'there is a lock which is opened by all keys (&&,<#1 --> lock>,<<$2 --> key> ==> <#1 --> (/,open,$2,_)>>). %1.00;0.90% 'key1 is a key <{key1} --> key>. %1.00;0.90% 5 'there is a lock which is opened by key1 ''outputMustContain('') //''outputMustContain('(&&,<#1 --> (/,open,{key1},_)>,<#1 --> lock>). %1.00;0.81%')