Description: Contraposition property of a polarity. (Contributed by NM, 26-Nov-2014) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypotheses | lpolcon.v | |
|
lpolcon.p | |
||
lpolcon.w | |
||
lpolcon.o | |
||
lpolcon.x | |
||
lpolcon.y | |
||
lpolcon.c | |
||
Assertion | lpolconN | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | lpolcon.v | |
|
2 | lpolcon.p | |
|
3 | lpolcon.w | |
|
4 | lpolcon.o | |
|
5 | lpolcon.x | |
|
6 | lpolcon.y | |
|
7 | lpolcon.c | |
|
8 | eqid | |
|
9 | eqid | |
|
10 | eqid | |
|
11 | eqid | |
|
12 | 1 8 9 10 11 2 | islpolN | |
13 | 3 12 | syl | |
14 | 4 13 | mpbid | |
15 | simpr2 | |
|
16 | 5 6 7 | 3jca | |
17 | 1 | fvexi | |
18 | 17 | elpw2 | |
19 | 5 18 | sylibr | |
20 | 17 | elpw2 | |
21 | 6 20 | sylibr | |
22 | sseq1 | |
|
23 | biidd | |
|
24 | sseq1 | |
|
25 | 22 23 24 | 3anbi123d | |
26 | fveq2 | |
|
27 | 26 | sseq2d | |
28 | 25 27 | imbi12d | |
29 | biidd | |
|
30 | sseq1 | |
|
31 | sseq2 | |
|
32 | 29 30 31 | 3anbi123d | |
33 | fveq2 | |
|
34 | 33 | sseq1d | |
35 | 32 34 | imbi12d | |
36 | 28 35 | sylan9bb | |
37 | 36 | spc2gv | |
38 | 19 21 37 | syl2anc | |
39 | 16 38 | mpid | |
40 | 15 39 | syl5 | |
41 | 14 40 | mpd | |