class com.meyling.principia.logic.basic.Conjunction
class com.meyling.principia.logic.basic.Disjunction
class com.meyling.principia.logic.basic.Equivalence
class com.meyling.principia.logic.basic.Implication
class com.meyling.principia.logic.basic.Negation (implements com.meyling.principia.argument.Argument, com.meyling.principia.logic.basic.Formula)
class com.meyling.principia.logic.basic.PredicateVariable (implements com.meyling.principia.argument.Argument, com.meyling.principia.logic.basic.Formula)
class com.meyling.principia.logic.basic.PropositionVariable (implements com.meyling.principia.argument.Argument, com.meyling.principia.logic.basic.Formula)
class com.meyling.principia.logic.basic.Quantifier (implements com.meyling.principia.argument.Argument, com.meyling.principia.logic.basic.Formula)