Metamath Proof Explorer


Theorem pmtrdifellem2

Description: Lemma 2 for pmtrdifel . (Contributed by AV, 15-Jan-2019)

Ref Expression
Hypotheses pmtrdifel.t T = ran pmTrsp N K
pmtrdifel.r R = ran pmTrsp N
pmtrdifel.0 S = pmTrsp N dom Q I
Assertion pmtrdifellem2 Q T dom S I = dom Q I

Proof

Step Hyp Ref Expression
1 pmtrdifel.t T = ran pmTrsp N K
2 pmtrdifel.r R = ran pmTrsp N
3 pmtrdifel.0 S = pmTrsp N dom Q I
4 3 difeq1i S I = pmTrsp N dom Q I I
5 4 dmeqi dom S I = dom pmTrsp N dom Q I I
6 eqid pmTrsp N K = pmTrsp N K
7 6 1 pmtrfb Q T N K V Q : N K 1-1 onto N K dom Q I 2 𝑜
8 difsnexi N K V N V
9 f1of Q : N K 1-1 onto N K Q : N K N K
10 fdm Q : N K N K dom Q = N K
11 difssd dom Q = N K Q I Q
12 dmss Q I Q dom Q I dom Q
13 11 12 syl dom Q = N K dom Q I dom Q
14 difssd dom Q = N K N K N
15 sseq1 dom Q = N K dom Q N N K N
16 14 15 mpbird dom Q = N K dom Q N
17 13 16 sstrd dom Q = N K dom Q I N
18 9 10 17 3syl Q : N K 1-1 onto N K dom Q I N
19 id dom Q I 2 𝑜 dom Q I 2 𝑜
20 8 18 19 3anim123i N K V Q : N K 1-1 onto N K dom Q I 2 𝑜 N V dom Q I N dom Q I 2 𝑜
21 7 20 sylbi Q T N V dom Q I N dom Q I 2 𝑜
22 eqid pmTrsp N = pmTrsp N
23 22 pmtrmvd N V dom Q I N dom Q I 2 𝑜 dom pmTrsp N dom Q I I = dom Q I
24 21 23 syl Q T dom pmTrsp N dom Q I I = dom Q I
25 5 24 syl5eq Q T dom S I = dom Q I