Metamath Proof Explorer


Theorem sgrim

Description: The induced metric on a subgroup is the induced metric on the parent group equipped with a norm. (Contributed by NM, 1-Feb-2008) (Revised by AV, 19-Oct-2021)

Ref Expression
Hypotheses sgrim.x
|- X = ( T |`s U )
sgrim.d
|- D = ( dist ` T )
sgrim.e
|- E = ( dist ` X )
Assertion sgrim
|- ( U e. S -> E = D )

Proof

Step Hyp Ref Expression
1 sgrim.x
 |-  X = ( T |`s U )
2 sgrim.d
 |-  D = ( dist ` T )
3 sgrim.e
 |-  E = ( dist ` X )
4 1 2 ressds
 |-  ( U e. S -> D = ( dist ` X ) )
5 3 4 eqtr4id
 |-  ( U e. S -> E = D )