Metamath Proof Explorer


Theorem stoweidlem33

Description: If a set of real functions from a common domain is closed under addition, multiplication and it contains constants, then it is closed under subtraction. (Contributed by Glauco Siliprandi, 20-Apr-2017)

Ref Expression
Hypotheses stoweidlem33.1 _tF
stoweidlem33.2 _tG
stoweidlem33.3 tφ
stoweidlem33.4 φfAf:T
stoweidlem33.5 φfAgAtTft+gtA
stoweidlem33.6 φfAgAtTftgtA
stoweidlem33.7 φxtTxA
Assertion stoweidlem33 φFAGAtTFtGtA

Proof

Step Hyp Ref Expression
1 stoweidlem33.1 _tF
2 stoweidlem33.2 _tG
3 stoweidlem33.3 tφ
4 stoweidlem33.4 φfAf:T
5 stoweidlem33.5 φfAgAtTft+gtA
6 stoweidlem33.6 φfAgAtTftgtA
7 stoweidlem33.7 φxtTxA
8 eqid tTFtGt=tTFtGt
9 eqid tT1=tT1
10 eqid tTtT1tGt=tTtT1tGt
11 3 1 2 8 9 10 4 5 6 7 stoweidlem22 φFAGAtTFtGtA