two propositions are contradictories if both cannot be true (or both cannot be false) at the same time
Adjective
unable to be both true at the same time - mutually exclusive
in disagreement "the figures are at odds with our findings" "contradictory attributes of unjust justice and loving vindictiveness"- John Morley - at odds- self contradictory
that confounds or contradicts or confuses
of words or propositions so related that both cannot be true and both cannot be false "`perfect' and `imperfect' are contradictory terms"