Description: Weak version of seqex that holds without ax-rep . A sequence builder exists when its binary operation input exists and its starting index is an integer. (Contributed by Rohan Ridenour, 14-Aug-2023)
Ref | Expression | ||
---|---|---|---|
Hypotheses | seqexw.1 | |
|
seqexw.2 | |
||
Assertion | seqexw | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | seqexw.1 | |
|
2 | seqexw.2 | |
|
3 | seqfn | |
|
4 | 2 3 | ax-mp | |
5 | fnfun | |
|
6 | 4 5 | ax-mp | |
7 | 4 | fndmi | |
8 | fvex | |
|
9 | 7 8 | eqeltri | |
10 | 1 | rnex | |
11 | prex | |
|
12 | 10 11 | unex | |
13 | fveq2 | |
|
14 | 13 | eleq1d | |
15 | fveq2 | |
|
16 | 15 | eleq1d | |
17 | fveq2 | |
|
18 | 17 | eleq1d | |
19 | fveq2 | |
|
20 | 19 | eleq1d | |
21 | seq1 | |
|
22 | ssun2 | |
|
23 | fvex | |
|
24 | 23 | prid2 | |
25 | 22 24 | sselii | |
26 | 21 25 | eqeltrdi | |
27 | seqp1 | |
|
28 | 27 | adantr | |
29 | df-ov | |
|
30 | snsspr1 | |
|
31 | unss2 | |
|
32 | 30 31 | ax-mp | |
33 | fvrn0 | |
|
34 | 32 33 | sselii | |
35 | 29 34 | eqeltri | |
36 | 35 | a1i | |
37 | 28 36 | eqeltrd | |
38 | 37 | ex | |
39 | 14 16 18 20 26 38 | uzind4 | |
40 | 39 | rgen | |
41 | fnfvrnss | |
|
42 | 4 40 41 | mp2an | |
43 | 12 42 | ssexi | |
44 | funexw | |
|
45 | 6 9 43 44 | mp3an | |