I guess you could claim one opposite of a tautology is an oxymoron.
"diction".the root is not diction, it is:dict (Latin root "to say")add the prefix "contra-" get the verb: contradict = to speak againstadd the suffix "-ion" to make it a noun: contradiction
Proof in which one assumes the opposite of what you have to prove is indirect proof. In indirect proof a person can draw a conclusion from assuming the opposite is true and then find a conclusion.
Some examples of contradictory terms are 'living dead', 'pretty ugly', 'jumbo shrimp', and 'virtual reality'. If the contradiction is intentional (rhetorical or poetic), then it is called an ox·y·mo·ron. All oxymorons are contradictory terms, but not all contradictory terms are oxymorons.OXYMORON n.A rhetorical figure in which incongruous or contradictory terms are combined, as in a deafening silence and a mournful optimist.
An implicit contradiction, as opposed to an explicit contradiction, is hidden within the logical structure of the statement. If you figure it out, you will discover that there is a contradiction. Explicit contradictions don't have to be figured out, they merely have to be pointed out.
To prove by contradiction, you assume that an opposite assumption is true, then disprove the opposite statement.
A contradiction occurs when two statements or ideas conflict with each other, leading to a logical inconsistency. This means that both statements cannot be true at the same time. In formal logic, a contradiction can invalidate an argument or theory.
contradiction, countermand, opposition, recall, reversal, revocation
footsoldier
opposite
Contradiction or indirect proof.
true
proof by contradiction
Contradiction is logical incompatibility between two or more things. When two propositions have two conclusions that are opposite inversions of each other a contradiction is formed.
Proof by contradiction (APEX)
Proof by contradiction (APEX)
conflict, inconsistency, contravention, incongruity, negation, opposite, denial