Theorem wfis2 5861

Description: Well Founded Induction schema, using implicit substitution. (Contributed by Scott Fenton, 29-Jan-2011.)

Hypotheses

Ref	Expression
wfis2.1	⊢ 𝑅 We 𝐴
wfis2.2	⊢ 𝑅 Se 𝐴
wfis2.3	⊢ (𝑦 = 𝑧 → (𝜑 ↔ 𝜓))
wfis2.4	⊢ (𝑦 ∈ 𝐴 → (∀𝑧 ∈ Pred (𝑅, 𝐴, 𝑦)𝜓 → 𝜑))

Assertion

Ref	Expression
wfis2	⊢ (𝑦 ∈ 𝐴 → 𝜑)

Distinct variable groups:   𝑦,𝐴,𝑧   𝜑,𝑧   𝜓,𝑦   𝑦,𝑅,𝑧

Allowed substitution hints:   𝜑(𝑦)   𝜓(𝑧)

Proof of Theorem wfis2

Step	Hyp	Ref	Expression
1		wfis2.1	. . 3 ⊢ 𝑅 We 𝐴
2		wfis2.2	. . 3 ⊢ 𝑅 Se 𝐴
3		wfis2.3	. . . 4 ⊢ (𝑦 = 𝑧 → (𝜑 ↔ 𝜓))
4		wfis2.4	. . . 4 ⊢ (𝑦 ∈ 𝐴 → (∀𝑧 ∈ Pred (𝑅, 𝐴, 𝑦)𝜓 → 𝜑))
5	3, 4	wfis2g 5860	. . 3 ⊢ ((𝑅 We 𝐴 ∧ 𝑅 Se 𝐴) → ∀𝑦 ∈ 𝐴 𝜑)
6	1, 2, 5	mp2an 672	. 2 ⊢ ∀𝑦 ∈ 𝐴 𝜑
7	6	rspec 3080	1 ⊢ (𝑦 ∈ 𝐴 → 𝜑)

Syntax hints:   → wi 4   ↔ wb 196   ∈ wcel 2145  ∀wral 3061   Se wse 5206   We wwe 5207  Predcpred 5820

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1870  ax-4 1885  ax-5 1991  ax-6 2057  ax-7 2093  ax-9 2154  ax-10 2174  ax-11 2190  ax-12 2203  ax-13 2408  ax-ext 2751  ax-sep 4915  ax-nul 4923  ax-pr 5034

This theorem depends on definitions:  df-bi 197  df-an 383  df-or 837  df-3or 1072  df-3an 1073  df-tru 1634  df-ex 1853  df-nf 1858  df-sb 2050  df-eu 2622  df-mo 2623  df-clab 2758  df-cleq 2764  df-clel 2767  df-nfc 2902  df-ne 2944  df-ral 3066  df-rex 3067  df-reu 3068  df-rmo 3069  df-rab 3070  df-v 3353  df-sbc 3588  df-dif 3726  df-un 3728  df-in 3730  df-ss 3737  df-nul 4064  df-if 4226  df-sn 4317  df-pr 4319  df-op 4323  df-br 4787  df-opab 4847  df-po 5170  df-so 5171  df-fr 5208  df-se 5209  df-we 5210  df-xp 5255  df-cnv 5257  df-dm 5259  df-rn 5260  df-res 5261  df-ima 5262  df-pred 5821

This theorem is referenced by:  wfis3  5862