Nuprl Lemma : context-subset_functionality

[Gamma:j⊢]. ∀[a,b:{Gamma ⊢ _:𝔽}].  (Gamma ⊢ (a ⇐⇒ b)  {Gamma, a ⊢ _} ≡ {Gamma, b ⊢ _})


Proof




Definitions occuring in Statement :  face-term-iff: Gamma ⊢ (phi ⇐⇒ psi) context-subset: Gamma, phi face-type: 𝔽 cubical-term: {X ⊢ _:A} cubical-type: {X ⊢ _} cubical_set: CubicalSet ext-eq: A ≡ B uall: [x:A]. B[x] implies:  Q
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T implies:  Q face-term-iff: Gamma ⊢ (phi ⇐⇒ psi) and: P ∧ Q ext-eq: A ≡ B uimplies: supposing a face-term-implies: Gamma ⊢ (phi  psi) prop: subtype_rel: A ⊆B
Lemmas referenced :  context-subset-subtype face-term-iff_wf cubical-term_wf face-type_wf cubical_set_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut lambdaFormation_alt sqequalHypSubstitution productElimination thin independent_pairFormation extract_by_obid isectElimination hypothesisEquality independent_isectElimination hypothesis because_Cache universeIsType instantiate sqequalRule lambdaEquality_alt dependent_functionElimination independent_pairEquality axiomEquality functionIsTypeImplies inhabitedIsType isect_memberEquality_alt isectIsTypeImplies

Latex:
\mforall{}[Gamma:j\mvdash{}].  \mforall{}[a,b:\{Gamma  \mvdash{}  \_:\mBbbF{}\}].    (Gamma  \mvdash{}  (a  \mLeftarrow{}{}\mRightarrow{}  b)  {}\mRightarrow{}  \{Gamma,  a  \mvdash{}  \_\}  \mequiv{}  \{Gamma,  b  \mvdash{}  \_\})



Date html generated: 2020_05_20-PM-02_51_36
Last ObjectModification: 2020_04_06-AM-10_32_20

Theory : cubical!type!theory


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