Nuprl Lemma : decidable__implies

[P:ℙ]. ∀[Q:⋂p:P. ℙ].  (Dec(P)  (P  Dec(Q))  Dec(P  Q))


Proof




Definitions occuring in Statement :  decidable: Dec(P) uall: [x:A]. B[x] prop: implies:  Q isect: x:A. B[x]
Definitions unfolded in proof :  decidable: Dec(P) uall: [x:A]. B[x] implies:  Q or: P ∨ Q member: t ∈ T prop: subtype_rel: A ⊆B guard: {T} not: ¬A false: False
Lemmas referenced :  not_wf or_wf
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep Error :isect_memberFormation_alt,  lambdaFormation sqequalHypSubstitution unionElimination thin independent_functionElimination hypothesis inlFormation hypothesisEquality cut introduction extract_by_obid isectElimination functionEquality applyEquality lambdaEquality rename equalityTransitivity equalitySymmetry isectEquality cumulativity universeEquality inrFormation voidElimination because_Cache Error :isectIsType,  Error :universeIsType,  Error :inhabitedIsType

Latex:
\mforall{}[P:\mBbbP{}].  \mforall{}[Q:\mcap{}p:P.  \mBbbP{}].    (Dec(P)  {}\mRightarrow{}  (P  {}\mRightarrow{}  Dec(Q))  {}\mRightarrow{}  Dec(P  {}\mRightarrow{}  Q))



Date html generated: 2019_06_20-AM-11_14_58
Last ObjectModification: 2018_09_26-AM-10_42_05

Theory : core_2


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