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