"propositions" . . . . . . "stated formally" . . "theorem in the mathematical sense" . . . . "Theorem" . "mathematical theorems" . . "theorems" . "mathematical theorem" . . . . . "logical theorems" . "corollary" . . "theorem" . . . . . . . "Theorem" . "Theorem terminology" . . . "proposition" . . . . . "Theorem#Terminology" . "converse" . . . . . "Theorem#Theorems in logic" .