| positive | all literals are positive | 
| negative | all literals are negative | 
| mixed | contains positive literals and negative literals | 
| unit | exactly one literal | 
| horn | the clause has at most one positive literal | 
| definite | the clause has exactly one positive literal | 
| has_equality | contains a positive or negative equality literal | 
| true | true in interpretations(s) | 
| false | false in interpretations(s) | 
| hint | the clause matches a hint | 
| initial | the clause was present before the selection of the first given clause | 
| resolvent | the clause is a (binary) resolvent | 
| hyper_resolvent | the clause is a hyperresolvent | 
| ur_resolvent | the clause is a unit-resulting (UR) resolvent | 
| factor | the clause is a (binary) factor | 
| paramodulant | the clause is a paramodulant | 
| back_demodulant | the clause is a back demodulant | 
| subsumer | the clause back subsumed another clause | 
| all | all clauses have this property |