Nuprl Lemma : trivial-same-context-set

X,Y:?CubicalContext.
  ((Y bind-provision(X;ctxt.OK(ctxt)) ∈ ?CubicalContext)
   context-ok(X)
   {(X Y ∈ ?CubicalContext) ∧ (context-set(X) context-set(Y) ∈ CubicalSet''')})


Proof




Definitions occuring in Statement :  context-set: context-set(ctxt) context-ok: context-ok(ctxt) cubical-context: ?CubicalContext cubical_set: CubicalSet guard: {T} all: x:A. B[x] implies:  Q and: P ∧ Q true: True equal: t ∈ T bind-provision: bind-provision(x;t.f[t]) provision: provision(ok; v)
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T implies:  Q guard: {T} and: P ∧ Q squash: T uall: [x:A]. B[x] prop: uimplies: supposing a true: True subtype_rel: A ⊆B iff: ⇐⇒ Q rev_implies:  Q cubical-context: ?CubicalContext so_lambda: λ2x.t[x] so_apply: x[s]
Lemmas referenced :  trivial-same-cubical-context cubical-context_wf equal_wf squash_wf true_wf istype-universe cubical_set_wf context-set_wf context-ok_wf subtype_rel_self iff_weakening_equal bind-provision_wf cubical_context_wf provision_wf istype-true allowed_wf allow_wf
Rules used in proof :  cut introduction extract_by_obid sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation_alt hypothesis sqequalHypSubstitution dependent_functionElimination thin hypothesisEquality independent_functionElimination inhabitedIsType universeIsType independent_pairFormation applyEquality instantiate lambdaEquality_alt imageElimination isectElimination equalityTransitivity equalitySymmetry universeEquality independent_isectElimination sqequalRule imageMemberEquality baseClosed because_Cache natural_numberEquality productElimination equalityIstype cumulativity isect_memberEquality_alt setElimination rename setIsType productIsType

Latex:
\mforall{}X,Y:?CubicalContext.
    ((Y  =  bind-provision(X;ctxt.OK(ctxt)))
    {}\mRightarrow{}  context-ok(X)
    {}\mRightarrow{}  \{(X  =  Y)  \mwedge{}  (context-set(X)  =  context-set(Y))\})



Date html generated: 2020_05_20-PM-08_07_19
Last ObjectModification: 2020_05_18-PM-03_02_49

Theory : cubical!type!theory


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