Nuprl Lemma : sq_or_functionality_wrt_iff

∀[P1,P2,Q1,Q2:ℙ].  ({P1 ⇐⇒ P2} ⇒ {Q1 ⇐⇒ Q2} ⇒ {P1 ↓∨ Q1 ⇐⇒ P2 ↓∨ Q2})


Proof




Definitions occuring in Statement :  sq_or: a ↓∨ b,  uall: ∀[x:A]. B[x],  prop: ℙ,  guard: {T},  iff: P ⇐⇒ Q,  implies: P ⇒ Q
Definitions unfolded in proof :  guard: {T},  sq_or: a ↓∨ b,  uall: ∀[x:A]. B[x],  member: t ∈ T,  implies: P ⇒ Q,  iff: P ⇐⇒ Q,  and: P ∧ Q,  squash: ↓T,  or: P ∨ Q,  prop: ℙ,  rev_implies: P ⇐ Q
Lemmas referenced :  iff_wf,  or_wf,  squash_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation,  introduction,  cut,  lambdaFormation,  sqequalHypSubstitution,  productElimination,  thin,  independent_pairFormation,  imageElimination,  unionElimination,  independent_functionElimination,  hypothesis,  inlFormation,  hypothesisEquality,  imageMemberEquality,  baseClosed,  inrFormation,  lemma_by_obid,  isectElimination,  lambdaEquality,  dependent_functionElimination,  independent_pairEquality,  universeEquality,  isect_memberEquality,  because_Cache

Latex:
\mforall{}[P1,P2,Q1,Q2:\mBbbP{}].    (\{P1  \mLeftarrow{}{}\mRightarrow{}  P2\}  {}\mRightarrow{}  \{Q1  \mLeftarrow{}{}\mRightarrow{}  Q2\}  {}\mRightarrow{}  \{P1  \mdownarrow{}\mvee{}  Q1  \mLeftarrow{}{}\mRightarrow{}  P2  \mdownarrow{}\mvee{}  Q2\})



Date html generated: 2016_05_13-PM-03_13_28
Last ObjectModification: 2016_01_06-PM-05_48_08

Theory : core_2


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