Metamath Proof Explorer


Theorem vtocl3gaOLD

Description: Obsolete version of vtocl3ga as of 3-Oct-2024. (Contributed by NM, 20-Aug-1995) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses vtocl3gaOLD.1 ( 𝑥 = 𝐴 → ( 𝜑𝜓 ) )
vtocl3gaOLD.2 ( 𝑦 = 𝐵 → ( 𝜓𝜒 ) )
vtocl3gaOLD.3 ( 𝑧 = 𝐶 → ( 𝜒𝜃 ) )
vtocl3gaOLD.4 ( ( 𝑥𝐷𝑦𝑅𝑧𝑆 ) → 𝜑 )
Assertion vtocl3gaOLD ( ( 𝐴𝐷𝐵𝑅𝐶𝑆 ) → 𝜃 )

Proof

Step Hyp Ref Expression
1 vtocl3gaOLD.1 ( 𝑥 = 𝐴 → ( 𝜑𝜓 ) )
2 vtocl3gaOLD.2 ( 𝑦 = 𝐵 → ( 𝜓𝜒 ) )
3 vtocl3gaOLD.3 ( 𝑧 = 𝐶 → ( 𝜒𝜃 ) )
4 vtocl3gaOLD.4 ( ( 𝑥𝐷𝑦𝑅𝑧𝑆 ) → 𝜑 )
5 nfcv 𝑥 𝐴
6 nfcv 𝑦 𝐴
7 nfcv 𝑧 𝐴
8 nfcv 𝑦 𝐵
9 nfcv 𝑧 𝐵
10 nfcv 𝑧 𝐶
11 nfv 𝑥 𝜓
12 nfv 𝑦 𝜒
13 nfv 𝑧 𝜃
14 5 6 7 8 9 10 11 12 13 1 2 3 4 vtocl3gaf ( ( 𝐴𝐷𝐵𝑅𝐶𝑆 ) → 𝜃 )