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: guard: {T} iff: ⇐⇒ Q implies:  Q union: left right
Definitions unfolded in proof :  guard: {T} or: P ∨ Q uall: [x:A]. B[x] implies:  Q iff: ⇐⇒ Q and: P ∧ Q member: t ∈ T prop: rev_implies:  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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