Metamath Proof Explorer


Theorem fzuntd

Description: Union of two adjacent finite sets of sequential integers that share a common endpoint. (Contributed by RP, 14-Dec-2024)

Ref Expression
Hypotheses fzuntd.k φ K
fzuntd.m φ M
fzuntd.n φ N
fzuntd.km φ K M
fzuntd.mn φ M N
Assertion fzuntd φ K M M N = K N

Proof

Step Hyp Ref Expression
1 fzuntd.k φ K
2 fzuntd.m φ M
3 fzuntd.n φ N
4 fzuntd.km φ K M
5 fzuntd.mn φ M N
6 simprl φ j j M j
7 6 zred φ j j M j
8 2 zred φ M
9 8 adantr φ j j M M
10 3 zred φ N
11 10 adantr φ j j M N
12 simprr φ j j M j M
13 5 adantr φ j j M M N
14 7 9 11 12 13 letrd φ j j M j N
15 14 expr φ j j M j N
16 15 anim2d φ j K j j M K j j N
17 1 zred φ K
18 17 adantr φ j M j K
19 8 adantr φ j M j M
20 simprl φ j M j j
21 20 zred φ j M j j
22 4 adantr φ j M j K M
23 simprr φ j M j M j
24 18 19 21 22 23 letrd φ j M j K j
25 24 expr φ j M j K j
26 25 anim1d φ j M j j N K j j N
27 16 26 jaod φ j K j j M M j j N K j j N
28 orc K j K j M j
29 orc K j K j j N
30 28 29 jca K j K j M j K j j N
31 30 ad2antrl φ j K j j N K j M j K j j N
32 simpr φ j j
33 32 zred φ j j
34 8 adantr φ j M
35 33 34 letrid φ j j M M j
36 35 adantr φ j K j j N j M M j
37 simprr φ j K j j N j N
38 37 olcd φ j K j j N j M j N
39 36 38 jca φ j K j j N j M M j j M j N
40 orddi K j j M M j j N K j M j K j j N j M M j j M j N
41 31 39 40 sylanbrc φ j K j j N K j j M M j j N
42 41 ex φ j K j j N K j j M M j j N
43 27 42 impbid φ j K j j M M j j N K j j N
44 43 pm5.32da φ j K j j M M j j N j K j j N
45 elfz1 K M j K M j K j j M
46 1 2 45 syl2anc φ j K M j K j j M
47 3anass j K j j M j K j j M
48 46 47 bitrdi φ j K M j K j j M
49 elfz1 M N j M N j M j j N
50 2 3 49 syl2anc φ j M N j M j j N
51 3anass j M j j N j M j j N
52 50 51 bitrdi φ j M N j M j j N
53 48 52 orbi12d φ j K M j M N j K j j M j M j j N
54 elun j K M M N j K M j M N
55 andi j K j j M M j j N j K j j M j M j j N
56 53 54 55 3bitr4g φ j K M M N j K j j M M j j N
57 elfz1 K N j K N j K j j N
58 1 3 57 syl2anc φ j K N j K j j N
59 3anass j K j j N j K j j N
60 58 59 bitrdi φ j K N j K j j N
61 44 56 60 3bitr4d φ j K M M N j K N
62 61 eqrdv φ K M M N = K N