Definition that contains logical relation
- contrary a logical relation such that two propositions are contraries if both cannot be true but both can be false
- illogical lacking in correct logical relation
- implication a logical relation between propositions p and q of the form `if p then q'; if p is true then q cannot be false
- conditional relation a logical relation between propositions p and q of the form `if p then q'; if p is true then q cannot be false
- logical implication a logical relation between propositions p and q of the form `if p then q'; if p is true then q cannot be false
- unlogical lacking in correct logical relation