Metamath Proof Explorer


Theorem mzpcl34

Description: Defining properties 3 and 4 of a polynomially closed function set P : it is closed under pointwise addition and multiplication. (Contributed by Stefan O'Rear, 4-Oct-2014)

Ref Expression
Assertion mzpcl34 PmzPolyCldVFPGPF+fGPF×fGP

Proof

Step Hyp Ref Expression
1 simp2 PmzPolyCldVFPGPFP
2 simp3 PmzPolyCldVFPGPGP
3 simp1 PmzPolyCldVFPGPPmzPolyCldV
4 3 elfvexd PmzPolyCldVFPGPVV
5 elmzpcl VVPmzPolyCldVPVfV×fPfVgVgfPfPgPf+fgPf×fgP
6 4 5 syl PmzPolyCldVFPGPPmzPolyCldVPVfV×fPfVgVgfPfPgPf+fgPf×fgP
7 3 6 mpbid PmzPolyCldVFPGPPVfV×fPfVgVgfPfPgPf+fgPf×fgP
8 7 simprrd PmzPolyCldVFPGPfPgPf+fgPf×fgP
9 oveq1 f=Ff+fg=F+fg
10 9 eleq1d f=Ff+fgPF+fgP
11 oveq1 f=Ff×fg=F×fg
12 11 eleq1d f=Ff×fgPF×fgP
13 10 12 anbi12d f=Ff+fgPf×fgPF+fgPF×fgP
14 oveq2 g=GF+fg=F+fG
15 14 eleq1d g=GF+fgPF+fGP
16 oveq2 g=GF×fg=F×fG
17 16 eleq1d g=GF×fgPF×fGP
18 15 17 anbi12d g=GF+fgPF×fgPF+fGPF×fGP
19 13 18 rspc2va FPGPfPgPf+fgPf×fgPF+fGPF×fGP
20 1 2 8 19 syl21anc PmzPolyCldVFPGPF+fGPF×fGP