Metamath Proof Explorer


Theorem tz7.48-2

Description: Proposition 7.48(2) of TakeutiZaring p. 51. (Contributed by NM, 9-Feb-1997) (Revised by David Abernethy, 5-May-2013)

Ref Expression
Hypothesis tz7.48.1 F Fn On
Assertion tz7.48-2 x On F x A F x Fun F -1

Proof

Step Hyp Ref Expression
1 tz7.48.1 F Fn On
2 ssid On On
3 onelon x On y x y On
4 3 ancoms y x x On y On
5 1 fndmi dom F = On
6 5 eleq2i y dom F y On
7 fnfun F Fn On Fun F
8 1 7 ax-mp Fun F
9 funfvima Fun F y dom F y x F y F x
10 8 9 mpan y dom F y x F y F x
11 10 impcom y x y dom F F y F x
12 eleq1a F y F x F x = F y F x F x
13 eldifn F x A F x ¬ F x F x
14 12 13 nsyli F y F x F x A F x ¬ F x = F y
15 11 14 syl y x y dom F F x A F x ¬ F x = F y
16 6 15 sylan2br y x y On F x A F x ¬ F x = F y
17 4 16 syldan y x x On F x A F x ¬ F x = F y
18 17 expimpd y x x On F x A F x ¬ F x = F y
19 18 com12 x On F x A F x y x ¬ F x = F y
20 19 ralrimiv x On F x A F x y x ¬ F x = F y
21 20 ralimiaa x On F x A F x x On y x ¬ F x = F y
22 1 tz7.48lem On On x On y x ¬ F x = F y Fun F On -1
23 2 21 22 sylancr x On F x A F x Fun F On -1
24 fnrel F Fn On Rel F
25 1 24 ax-mp Rel F
26 5 eqimssi dom F On
27 relssres Rel F dom F On F On = F
28 25 26 27 mp2an F On = F
29 28 cnveqi F On -1 = F -1
30 29 funeqi Fun F On -1 Fun F -1
31 23 30 sylib x On F x A F x Fun F -1