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: ℕ,  uall: ∀[x:A]. B[x],  prop: ℙ,  so_apply: x[s1;s2;s3],  implies: P ⇒ Q,  and: P ∧ Q,  function: x:A ⟶ B[x]
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  cubical-type-restriction: cubical-type-restriction,  all: ∀x:A. B[x],  and: P ∧ Q,  cand: A c∧ B,  member: t ∈ T,  so_apply: x[s1;s2;s3],  prop: ℙ,  subtype_rel: A ⊆r 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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