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: P ⇒ Q,  and: P ∧ Q,  true: True,  equal: s = 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: P ⇒ Q,  guard: {T},  and: P ∧ Q,  squash: ↓T,  uall: ∀[x:A]. B[x],  prop: ℙ,  uimplies: b supposing a,  true: True,  subtype_rel: A ⊆r B,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ 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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