TIMEOUT
MAYBE
Trs:
 {mark g -> g,
  mark d -> d,
  mark f -> a__f mark,
  mark c -> a__c,
  mark h -> a__h mark,
  a__f f -> a__c f g f,
    a__f -> f,
    a__c -> d,
    a__c -> c,
    a__h -> a__c d,
    a__h -> h}
 Open