Metamath Proof Explorer


Theorem tgrpbase

Description: The base set of the translation group is the set of all translations (for a fiducial co-atom W ). (Contributed by NM, 5-Jun-2013)

Ref Expression
Hypotheses tgrpset.h ⊢ H = LHyp ⁡ K
tgrpset.t ⊢ T = LTrn ⁡ K ⁡ W
tgrpset.g ⊢ G = TGrp ⁡ K ⁡ W
tgrp.c ⊢ C = Base G
Assertion tgrpbase ⊢ K ∈ V ∧ W ∈ H → C = T

Proof

Step Hyp Ref Expression
1 tgrpset.h ⊢ H = LHyp ⁡ K
2 tgrpset.t ⊢ T = LTrn ⁡ K ⁡ W
3 tgrpset.g ⊢ G = TGrp ⁡ K ⁡ W
4 tgrp.c ⊢ C = Base G
5 1 2 3 tgrpset ⊢ K ∈ V ∧ W ∈ H → G = Base ndx T + ndx f ∈ T , g ∈ T ⟼ f ∘ g
6 5 fveq2d ⊢ K ∈ V ∧ W ∈ H → Base G = Base Base ndx T + ndx f ∈ T , g ∈ T ⟼ f ∘ g
7 2 fvexi ⊢ T ∈ V
8 eqid ⊢ Base ndx T + ndx f ∈ T , g ∈ T ⟼ f ∘ g = Base ndx T + ndx f ∈ T , g ∈ T ⟼ f ∘ g
9 8 grpbase ⊢ T ∈ V → T = Base Base ndx T + ndx f ∈ T , g ∈ T ⟼ f ∘ g
10 7 9 ax-mp ⊢ T = Base Base ndx T + ndx f ∈ T , g ∈ T ⟼ f ∘ g
11 6 4 10 3eqtr4g ⊢ K ∈ V ∧ W ∈ H → C = T