Nuprl Lemma : union_functionality_wrt_iff

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


Proof




Definitions occuring in Statement :  uall: ∀[x:A]. B[x],  prop: ℙ,  guard: {T},  iff: P ⇐⇒ Q,  implies: P ⇒ Q,  union: left + right
Definitions unfolded in proof :  guard: {T},  or: P ∨ Q,  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  iff: P ⇐⇒ Q,  and: P ∧ Q,  member: t ∈ T,  prop: ℙ,  rev_implies: P ⇐ Q
Lemmas referenced :  or_wf,  iff_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  Error :isect_memberFormation_alt,  lambdaFormation,  sqequalHypSubstitution,  productElimination,  thin,  independent_pairFormation,  unionElimination,  inlFormation,  independent_functionElimination,  hypothesis,  hypothesisEquality,  inrFormation,  cut,  introduction,  extract_by_obid,  isectElimination,  Error :inhabitedIsType,  Error :universeIsType,  universeEquality

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



Date html generated: 2019_06_20-AM-11_17_19
Last ObjectModification: 2018_09_26-AM-10_24_46

Theory : core_2


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