| Answer | Crossword Clue |
|---|---|
| metalanguages | A system of propositions about propositions |
| metalanguage | A system of propositions about propositions |
| biconditional | a relation between two propositions that is true only when both propositions are simultaneously true or false |
| biconditionals | BICONDITIONAL, a relation between two propositions that is true only when both propositions are simultaneously true or false |
