Metamath Proof Explorer


Theorem riota2df

Description: A deduction version of riota2f . (Contributed by NM, 17-Feb-2013) (Revised by Mario Carneiro, 15-Oct-2016)

Ref Expression
Hypotheses riota2df.1 xφ
riota2df.2 φ_xB
riota2df.3 φxχ
riota2df.4 φBA
riota2df.5 φx=Bψχ
Assertion riota2df φ∃!xAψχιxA|ψ=B

Proof

Step Hyp Ref Expression
1 riota2df.1 xφ
2 riota2df.2 φ_xB
3 riota2df.3 φxχ
4 riota2df.4 φBA
5 riota2df.5 φx=Bψχ
6 4 adantr φ∃!xAψBA
7 simpr φ∃!xAψ∃!xAψ
8 df-reu ∃!xAψ∃!xxAψ
9 7 8 sylib φ∃!xAψ∃!xxAψ
10 simpr φ∃!xAψx=Bx=B
11 6 adantr φ∃!xAψx=BBA
12 10 11 eqeltrd φ∃!xAψx=BxA
13 12 biantrurd φ∃!xAψx=BψxAψ
14 5 adantlr φ∃!xAψx=Bψχ
15 13 14 bitr3d φ∃!xAψx=BxAψχ
16 nfreu1 x∃!xAψ
17 1 16 nfan xφ∃!xAψ
18 3 adantr φ∃!xAψxχ
19 2 adantr φ∃!xAψ_xB
20 6 9 15 17 18 19 iota2df φ∃!xAψχιx|xAψ=B
21 df-riota ιxA|ψ=ιx|xAψ
22 21 eqeq1i ιxA|ψ=Bιx|xAψ=B
23 20 22 bitr4di φ∃!xAψχιxA|ψ=B