Nuprl Lemma : ps-sigma-elim-rule

∀[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[B:{X.A ⊢ _}]. ∀[T:{X.Σ A B ⊢ _}].
∀[t:{X.A.B ⊢ _:(T)SigmaUnElim}].
  ((t)SigmaElim ∈ {X.Σ A B ⊢ _:T})


Proof




Definitions occuring in Statement :  sigma-unelim-pscm: SigmaUnElim,  sigma-elim-pscm: SigmaElim,  presheaf-sigma: Σ A B,  psc-adjoin: X.A,  pscm-ap-term: (t)s,  presheaf-term: {X ⊢ _:A},  pscm-ap-type: (AF)s,  presheaf-type: {X ⊢ _},  ps_context: __⊢,  uall: ∀[x:A]. B[x],  member: t ∈ T,  small-category: SmallCategory
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  subtype_rel: A ⊆r B,  squash: ↓T,  prop: ℙ,  true: True,  uimplies: b supposing a,  guard: {T},  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q
Lemmas referenced :  pscm-ap-term_wf,  psc-adjoin_wf,  ps_context_cumulativity2,  presheaf-sigma_wf,  presheaf-type-cumulativity2,  pscm-ap-type_wf,  sigma-unelim-pscm_wf,  sigma-elim-pscm_wf,  presheaf-term_wf2,  squash_wf,  true_wf,  presheaf-type_wf,  ps_context_wf,  small-category-cumulativity-2,  small-category_wf,  equal_wf,  istype-universe,  pscm-ap-comp-type,  subtype_rel_self,  iff_weakening_equal,  pscm-ap-id-type,  psc_map_wf,  ps-sigma-elim-unelim
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  cut,  thin,  instantiate,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  applyEquality,  because_Cache,  hypothesis,  sqequalRule,  lambdaEquality_alt,  imageElimination,  equalityTransitivity,  equalitySymmetry,  universeIsType,  natural_numberEquality,  imageMemberEquality,  baseClosed,  hyp_replacement,  universeEquality,  independent_isectElimination,  productElimination,  independent_functionElimination,  inhabitedIsType

Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[B:\{X.A  \mvdash{}  \_\}].  \mforall{}[T:\{X.\mSigma{}  A  B  \mvdash{}  \_\}].
\mforall{}[t:\{X.A.B  \mvdash{}  \_:(T)SigmaUnElim\}].
    ((t)SigmaElim  \mmember{}  \{X.\mSigma{}  A  B  \mvdash{}  \_:T\})



Date html generated: 2020_05_20-PM-01_33_01
Last ObjectModification: 2020_04_02-PM-06_47_01

Theory : presheaf!models!of!type!theory


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