Metamath Proof Explorer


Theorem f1omvdmvd

Description: A permutation of any class moves a point which is moved to a different point which is moved. (Contributed by Stefan O'Rear, 22-Aug-2015)

Ref Expression
Assertion f1omvdmvd F : A 1-1 onto A X dom F I F X dom F I X

Proof

Step Hyp Ref Expression
1 simpr F : A 1-1 onto A X dom F I X dom F I
2 f1ofn F : A 1-1 onto A F Fn A
3 difss F I F
4 dmss F I F dom F I dom F
5 3 4 ax-mp dom F I dom F
6 f1odm F : A 1-1 onto A dom F = A
7 5 6 sseqtrid F : A 1-1 onto A dom F I A
8 7 sselda F : A 1-1 onto A X dom F I X A
9 fnelnfp F Fn A X A X dom F I F X X
10 2 8 9 syl2an2r F : A 1-1 onto A X dom F I X dom F I F X X
11 1 10 mpbid F : A 1-1 onto A X dom F I F X X
12 f1of1 F : A 1-1 onto A F : A 1-1 A
13 12 adantr F : A 1-1 onto A X dom F I F : A 1-1 A
14 f1of F : A 1-1 onto A F : A A
15 14 adantr F : A 1-1 onto A X dom F I F : A A
16 15 8 ffvelrnd F : A 1-1 onto A X dom F I F X A
17 f1fveq F : A 1-1 A F X A X A F F X = F X F X = X
18 13 16 8 17 syl12anc F : A 1-1 onto A X dom F I F F X = F X F X = X
19 18 necon3bid F : A 1-1 onto A X dom F I F F X F X F X X
20 11 19 mpbird F : A 1-1 onto A X dom F I F F X F X
21 fnelnfp F Fn A F X A F X dom F I F F X F X
22 2 16 21 syl2an2r F : A 1-1 onto A X dom F I F X dom F I F F X F X
23 20 22 mpbird F : A 1-1 onto A X dom F I F X dom F I
24 eldifsn F X dom F I X F X dom F I F X X
25 23 11 24 sylanbrc F : A 1-1 onto A X dom F I F X dom F I X