Theorem mtbid 662

Description: A deduction from a biconditional, similar to modus tollens. (Contributed by NM, 26-Nov-1995.)

Hypotheses

Ref	Expression
mtbid.min	⊢ (𝜑 → ¬ 𝜓)
mtbid.maj	⊢ (𝜑 → (𝜓 ↔ 𝜒))

Assertion

Ref	Expression
mtbid	⊢ (𝜑 → ¬ 𝜒)

Proof of Theorem mtbid

Step	Hyp	Ref	Expression
1		mtbid.min	. 2 ⊢ (𝜑 → ¬ 𝜓)
2		mtbid.maj	. . 3 ⊢ (𝜑 → (𝜓 ↔ 𝜒))
3	2	biimprd 157	. 2 ⊢ (𝜑 → (𝜒 → 𝜓))
4	1, 3	mtod 653	1 ⊢ (𝜑 → ¬ 𝜒)

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 104

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 604  ax-in2 605

This theorem depends on definitions:  df-bi 116

This theorem is referenced by:  sylnib  666  eqneltrrd  2237  neleqtrd  2238  eueq3dc  2862  efrirr  4283  fidcenumlemrks  6849  nqnq0pi  7270  zdclt  9152  xleaddadd  9700  frec2uzf1od  10210  expnegap0  10332  bcval5  10541  zfz1isolemiso  10614  seq3coll  10617  fisumss  11193  rpdvds  11816  oddpwdclemodd  11886  pwle2  13366