Nuprl Lemma : cubical-type-restriction-and

[X:j⊢]. ∀[T:{X ⊢ _}]. ∀[psi,phi:I:fset(ℕ) ⟶ alpha:X(I) ⟶ T(alpha) ⟶ ℙ].
  (cubical-type-restriction(X;T;I,a,t.psi[I;a;t])
   cubical-type-restriction(X;T;I,a,t.phi[I;a;t])
   cubical-type-restriction(X;T;I,a,t.psi[I;a;t] ∧ phi[I;a;t]))


Proof




Definitions occuring in Statement :  cubical-type-restriction: cubical-type-restriction cubical-type-at: A(a) cubical-type: {X ⊢ _} I_cube: A(I) cubical_set: CubicalSet fset: fset(T) nat: uall: [x:A]. B[x] prop: so_apply: x[s1;s2;s3] implies:  Q and: P ∧ Q function: x:A ⟶ B[x]
Definitions unfolded in proof :  uall: [x:A]. B[x] implies:  Q cubical-type-restriction: cubical-type-restriction all: x:A. B[x] and: P ∧ Q cand: c∧ B member: t ∈ T so_apply: x[s1;s2;s3] prop: subtype_rel: A ⊆B so_lambda: so_lambda3 guard: {T}
Lemmas referenced :  istype-cubical-type-at I_cube_wf names-hom_wf cubical-type-restriction_wf cubical_set_cumulativity-i-j cubical-type-cumulativity2 fset_wf nat_wf cubical-type_wf cubical_set_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt lambdaFormation_alt sqequalHypSubstitution productElimination thin cut independent_pairFormation hypothesis sqequalRule productIsType universeIsType applyEquality hypothesisEquality introduction extract_by_obid isectElimination because_Cache instantiate lambdaEquality_alt cumulativity inhabitedIsType functionIsType universeEquality dependent_functionElimination independent_functionElimination

Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[T:\{X  \mvdash{}  \_\}].  \mforall{}[psi,phi:I:fset(\mBbbN{})  {}\mrightarrow{}  alpha:X(I)  {}\mrightarrow{}  T(alpha)  {}\mrightarrow{}  \mBbbP{}].
    (cubical-type-restriction(X;T;I,a,t.psi[I;a;t])
    {}\mRightarrow{}  cubical-type-restriction(X;T;I,a,t.phi[I;a;t])
    {}\mRightarrow{}  cubical-type-restriction(X;T;I,a,t.psi[I;a;t]  \mwedge{}  phi[I;a;t]))



Date html generated: 2020_05_20-PM-03_13_11
Last ObjectModification: 2020_04_06-PM-05_17_17

Theory : cubical!type!theory


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