充分必要条件; Necessary and sufficient conditions;
必要充分条件; necessary and sufficient condition;
充分不必要条件;fully not necessary condition;
;必要不充分条件necessary but not sufficient condition;
;原命题;the original proposition;
;真值truth;
条件和结论分别是conditions and conclusions are
你否命题; you proposition;
逆命题inverse proposition
真值相同truth value the same
否命题negative proposition;
假命题false statement;
逆否命题inverse negative propositions