Metamath Proof Explorer


Theorem grpstr

Description: A constructed group is a structure. Version not depending on the implementation of the indices. (Contributed by AV, 27-Oct-2024)

Ref Expression
Hypothesis grpfn.g ⊢ G = Base ndx B + ndx + ˙
Assertion grpstr ⊢ G Struct Base ndx + ndx

Proof

Step Hyp Ref Expression
1 grpfn.g ⊢ G = Base ndx B + ndx + ˙
2 basendxltplusgndx ⊢ Base ndx < + ndx
3 plusgndxnn ⊢ + ndx ∈ ℕ
4 1 2 3 2strstr ⊢ G Struct Base ndx + ndx