Nuprl Lemma : psc_map_cumulativity2

∀[C:SmallCategory]. ∀[X,Y,Z,U:ps_context{j:l}(C)].
  (psc_map{j:l}(C; X; Z) ⊆r psc_map{j:l}(C; Y; U)) supposing 
     (sub_ps_context{j:l}(C; Y; X) and 
     sub_ps_context{j:l}(C; Z; U))


Proof




Definitions occuring in Statement :  sub_ps_context: Y ⊆ X,  psc_map: A ⟶ B,  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],  uimplies: b supposing a,  member: t ∈ T,  subtype_rel: A ⊆r B,  istype: istype(T)
Lemmas referenced :  sub_ps_context_wf,  ps_context_wf,  small-category-cumulativity-2,  small-category_wf,  psc_map_wf,  psc_map_subtype3,  subtype_rel_transitivity
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  universeIsType,  cut,  thin,  instantiate,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  applyEquality,  because_Cache,  hypothesis,  sqequalRule,  independent_isectElimination,  lambdaEquality_alt

Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X,Y,Z,U:ps\_context\{j:l\}(C)].
    (psc\_map\{j:l\}(C;  X;  Z)  \msubseteq{}r  psc\_map\{j:l\}(C;  Y;  U))  supposing 
          (sub\_ps\_context\{j:l\}(C;  Y;  X)  and 
          sub\_ps\_context\{j:l\}(C;  Z;  U))



Date html generated: 2020_05_20-PM-01_25_12
Last ObjectModification: 2020_04_01-PM-00_17_51

Theory : presheaf!models!of!type!theory


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