Metamath Proof Explorer


Theorem tendoid0

Description: A trace-preserving endomorphism is the additive identity iff at least one of its values (at a non-identity translation) is the identity translation. (Contributed by NM, 1-Aug-2013)

Ref Expression
Hypotheses tendoid0.b B = Base K
tendoid0.h H = LHyp K
tendoid0.t T = LTrn K W
tendoid0.e E = TEndo K W
tendoid0.o O = f T I B
Assertion tendoid0 K HL W H U E F T F I B U F = I B U = O

Proof

Step Hyp Ref Expression
1 tendoid0.b B = Base K
2 tendoid0.h H = LHyp K
3 tendoid0.t T = LTrn K W
4 tendoid0.e E = TEndo K W
5 tendoid0.o O = f T I B
6 simp3l K HL W H U E F T F I B F T
7 5 1 tendo02 F T O F = I B
8 6 7 syl K HL W H U E F T F I B O F = I B
9 8 eqeq2d K HL W H U E F T F I B U F = O F U F = I B
10 simpl1 K HL W H U E F T F I B U F = O F K HL W H
11 simpl2 K HL W H U E F T F I B U F = O F U E
12 1 2 3 4 5 tendo0cl K HL W H O E
13 10 12 syl K HL W H U E F T F I B U F = O F O E
14 simpr K HL W H U E F T F I B U F = O F U F = O F
15 simpl3l K HL W H U E F T F I B U F = O F F T
16 simpl3r K HL W H U E F T F I B U F = O F F I B
17 1 2 3 4 tendocan K HL W H U E O E U F = O F F T F I B U = O
18 10 11 13 14 15 16 17 syl132anc K HL W H U E F T F I B U F = O F U = O
19 18 ex K HL W H U E F T F I B U F = O F U = O
20 9 19 sylbird K HL W H U E F T F I B U F = I B U = O
21 fveq1 U = O U F = O F
22 21 eqeq1d U = O U F = I B O F = I B
23 8 22 syl5ibrcom K HL W H U E F T F I B U = O U F = I B
24 20 23 impbid K HL W H U E F T F I B U F = I B U = O