Metamath Proof Explorer


Theorem rnasclmulcl

Description: (Vector) multiplication is closed for scalar multiples of the unit vector. (Contributed by SN, 5-Nov-2023)

Ref Expression
Hypotheses rnasclmulcl.c
|- C = ( algSc ` W )
rnasclmulcl.x
|- .X. = ( .r ` W )
rnasclmulcl.w
|- ( ph -> W e. AssAlg )
Assertion rnasclmulcl
|- ( ( ph /\ ( X e. ran C /\ Y e. ran C ) ) -> ( X .X. Y ) e. ran C )

Proof

Step Hyp Ref Expression
1 rnasclmulcl.c
 |-  C = ( algSc ` W )
2 rnasclmulcl.x
 |-  .X. = ( .r ` W )
3 rnasclmulcl.w
 |-  ( ph -> W e. AssAlg )
4 1 3 rnasclsubrg
 |-  ( ph -> ran C e. ( SubRing ` W ) )
5 2 subrgmcl
 |-  ( ( ran C e. ( SubRing ` W ) /\ X e. ran C /\ Y e. ran C ) -> ( X .X. Y ) e. ran C )
6 4 5 syl3an1
 |-  ( ( ph /\ X e. ran C /\ Y e. ran C ) -> ( X .X. Y ) e. ran C )
7 6 3expb
 |-  ( ( ph /\ ( X e. ran C /\ Y e. ran C ) ) -> ( X .X. Y ) e. ran C )