Metamath Proof Explorer


Theorem efif1olem3

Description: Lemma for efif1o . (Contributed by Mario Carneiro, 8-May-2015)

Ref Expression
Hypotheses efif1o.1 F=wDeiw
efif1o.2 C=abs-11
Assertion efif1olem3 φxCx11

Proof

Step Hyp Ref Expression
1 efif1o.1 F=wDeiw
2 efif1o.2 C=abs-11
3 simpr φxCxC
4 3 2 eleqtrdi φxCxabs-11
5 absf abs:
6 ffn abs:absFn
7 fniniseg absFnxabs-11xx=1
8 5 6 7 mp2b xabs-11xx=1
9 4 8 sylib φxCxx=1
10 9 simpld φxCx
11 10 sqrtcld φxCx
12 11 imcld φxCx
13 absimle xxx
14 11 13 syl φxCxx
15 10 sqsqrtd φxCx2=x
16 15 fveq2d φxCx2=x
17 2nn0 20
18 absexp x20x2=x2
19 11 17 18 sylancl φxCx2=x2
20 9 simprd φxCx=1
21 16 19 20 3eqtr3d φxCx2=1
22 sq1 12=1
23 21 22 eqtr4di φxCx2=12
24 11 abscld φxCx
25 11 absge0d φxC0x
26 1re 1
27 0le1 01
28 sq11 x0x101x2=12x=1
29 26 27 28 mpanr12 x0xx2=12x=1
30 24 25 29 syl2anc φxCx2=12x=1
31 23 30 mpbid φxCx=1
32 14 31 breqtrd φxCx1
33 absle x1x11xx1
34 12 26 33 sylancl φxCx11xx1
35 32 34 mpbid φxC1xx1
36 35 simpld φxC1x
37 35 simprd φxCx1
38 neg1rr 1
39 38 26 elicc2i x11x1xx1
40 12 36 37 39 syl3anbrc φxCx11