Description: Closure of the power series multiplication operation. (Contributed by Mario Carneiro, 29-Dec-2014)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | psrmulcl.s | |- S = ( I mPwSer R ) | |
| psrmulcl.b | |- B = ( Base ` S ) | ||
| psrmulcl.t | |- .x. = ( .r ` S ) | ||
| psrmulcl.r | |- ( ph -> R e. Ring ) | ||
| psrmulcl.x | |- ( ph -> X e. B ) | ||
| psrmulcl.y | |- ( ph -> Y e. B ) | ||
| Assertion | psrmulcl | |- ( ph -> ( X .x. Y ) e. B ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | psrmulcl.s | |- S = ( I mPwSer R ) | |
| 2 | psrmulcl.b | |- B = ( Base ` S ) | |
| 3 | psrmulcl.t | |- .x. = ( .r ` S ) | |
| 4 | psrmulcl.r | |- ( ph -> R e. Ring ) | |
| 5 | psrmulcl.x | |- ( ph -> X e. B ) | |
| 6 | psrmulcl.y | |- ( ph -> Y e. B ) | |
| 7 | eqid |  |-  { f e. ( NN0 ^m I ) | ( `' f " NN ) e. Fin } = { f e. ( NN0 ^m I ) | ( `' f " NN ) e. Fin } | |
| 8 | 1 2 3 4 5 6 7 | psrmulcllem | |- ( ph -> ( X .x. Y ) e. B ) |