Theorems |
BIJ : !s t. BIJ s t = INJ s t INTER SURJ s tCHOICE : !s. ~(s = {}) ==> CHOICE s IN sCROSS : !s t. s CROSS t = {x,y | x IN s /\ y IN t}DELETE : !s x. s DELETE x = {y | y IN s /\ ~(y = x)}DIFF : !s t. s DIFF t = {x | x IN s /\ ~(x IN t)}DISJOINT : !s t. DISJOINT s t <=> s INTER t = {}EMPTY : {} = {x | F}EXTENSION_IMP : !s t. (!x. x IN s <=> x IN t) ==> s = tIMAGE : !f s. IMAGE f s = {y | ?x. x IN s /\ y = f x}INJ : !s t.
INJ s t =
{f | (!x. x IN s ==> f x IN t) /\
(!x y. x IN s /\ y IN s /\ f x = f y ==> x = y)}INSERT : !x s. x INSERT s = {y | y = x \/ y IN s}INTER : !s t. s INTER t = {x | x IN s /\ x IN t}INTERS : !s. INTERS s = {x | !u. u IN s ==> x IN u}IN_ELIM_THM : !p x. x IN GSPEC p <=> p xPSUBSET : !s t. s PSUBSET t <=> s SUBSET t /\ ~(s = t)REST : !s. REST s = s DELETE CHOICE sSING : !s. SING s <=> (?x. s = {x})SUBSET : !s t. s SUBSET t <=> (!x. x IN s ==> x IN t)SURJ : !s t.
SURJ s t =
{f | (!x. x IN s ==> f x IN t) /\
(!x. x IN t ==> (?y. y IN s /\ f y = x))}UNION : !s t. s UNION t = {x | x IN s \/ x IN t}UNIONS : !s. UNIONS s = {x | ?u. u IN s /\ x IN u}UNIV : UNIV = {x | T} |