Description: Lemma for rexdif1en and dif1en . (Contributed by BTernaryTau, 18-Aug-2024)
Ref | Expression | ||
---|---|---|---|
Assertion | dif1enlem | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simp1 | |
|
2 | sucidg | |
|
3 | dff1o3 | |
|
4 | 3 | simprbi | |
5 | 4 | adantr | |
6 | f1ofo | |
|
7 | f1ofn | |
|
8 | fnresdm | |
|
9 | foeq1 | |
|
10 | 7 8 9 | 3syl | |
11 | 6 10 | mpbird | |
12 | 11 | adantr | |
13 | 7 | adantr | |
14 | f1ocnvdm | |
|
15 | f1ocnvfv2 | |
|
16 | snidg | |
|
17 | 16 | adantl | |
18 | 15 17 | eqeltrd | |
19 | fressnfv | |
|
20 | 19 | biimp3ar | |
21 | 13 14 18 20 | syl3anc | |
22 | disjsn | |
|
23 | 22 | con2bii | |
24 | 14 23 | sylib | |
25 | fnresdisj | |
|
26 | 7 25 | syl | |
27 | 26 | adantr | |
28 | 24 27 | mtbid | |
29 | 28 | neqned | |
30 | foconst | |
|
31 | 21 29 30 | syl2anc | |
32 | resdif | |
|
33 | 5 12 31 32 | syl3anc | |
34 | 2 33 | sylan2 | |
35 | nnord | |
|
36 | orddif | |
|
37 | 35 36 | syl | |
38 | 37 | f1oeq3d | |
39 | 38 | adantl | |
40 | 34 39 | mpbird | |
41 | 40 | ancoms | |
42 | 41 | 3adant1 | |
43 | resexg | |
|
44 | f1oen3g | |
|
45 | 43 44 | sylan | |
46 | 1 42 45 | syl2anc | |