Nuprl Lemma : subset-presheaf-type

∀[C:SmallCategory]. ∀[X,Y:ps_context{j:l}(C)].  {X ⊢ _} ⊆r {Y ⊢ _} supposing sub_ps_context{j:l}(C; Y; X)


Proof




Definitions occuring in Statement :  presheaf-type: {X ⊢ _},  sub_ps_context: Y ⊆ X,  ps_context: __⊢,  uimplies: b supposing a,  subtype_rel: A ⊆r B,  uall: ∀[x:A]. B[x],  small-category: SmallCategory
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  subtype_rel: A ⊆r B,  sub_ps_context: Y ⊆ X,  presheaf-type: {X ⊢ _},  so_lambda: λ2x.t[x],  so_apply: x[s],  all: ∀x:A. B[x],  squash: ↓T,  prop: ℙ,  true: True,  guard: {T},  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  pscm-id: 1(X),  pscm-ap-type: (AF)s,  pscm-ap: (s)x
Lemmas referenced :  subset-I_set,  ps-subset-restriction,  presheaf-type-equal,  pscm-ap-type_wf,  subtype_rel_product,  cat-ob_wf,  I_set_wf,  cat-arrow_wf,  psc-restriction_wf,  istype-universe,  subtype_rel_dep_function,  subtype_rel-equal,  equal_wf,  squash_wf,  true_wf,  subtype_rel_self,  iff_weakening_equal,  presheaf-type_wf,  sub_ps_context_wf,  ps_context_wf,  small-category-cumulativity-2,  small-category_wf
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  independent_isectElimination,  lambdaEquality_alt,  setElimination,  rename,  applyEquality,  instantiate,  functionEquality,  cumulativity,  universeEquality,  sqequalRule,  functionIsType,  universeIsType,  because_Cache,  lambdaFormation_alt,  dependent_functionElimination,  inhabitedIsType,  imageElimination,  equalityTransitivity,  equalitySymmetry,  natural_numberEquality,  imageMemberEquality,  baseClosed,  productElimination,  independent_functionElimination,  dependent_pairEquality_alt,  axiomEquality,  functionExtensionality,  hyp_replacement

Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X,Y:ps\_context\{j:l\}(C)].
    \{X  \mvdash{}  \_\}  \msubseteq{}r  \{Y  \mvdash{}  \_\}  supposing  sub\_ps\_context\{j:l\}(C;  Y;  X)



Date html generated: 2020_05_20-PM-01_35_00
Last ObjectModification: 2020_04_02-PM-06_34_43

Theory : presheaf!models!of!type!theory


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