Nuprl Lemma : not-Sierpinski-top

∀[x:Sierpinski]. ((¬(x = ⊤ ∈ Sierpinski)) ⇒ (x = ⊥ ∈ Sierpinski))


Proof




Definitions occuring in Statement :  Sierpinski: Sierpinski,  Sierpinski-top: ⊤,  Sierpinski-bottom: ⊥,  uall: ∀[x:A]. B[x],  not: ¬A,  implies: P ⇒ Q,  equal: s = t ∈ T
Definitions unfolded in proof :  iff: P ⇐⇒ Q,  and: P ∧ Q,  uall: ∀[x:A]. B[x],  member: t ∈ T,  implies: P ⇒ Q,  Sierpinski: Sierpinski,  quotient: x,y:A//B[x; y],  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  uimplies: b supposing a,  all: ∀x:A. B[x],  prop: ℙ,  rev_implies: P ⇐ Q,  Sierpinski-bottom: ⊥,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  not: ¬A,  false: False,  bfalse: ff,  exists: ∃x:A. B[x],  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  ifthenelse: if b then t else f fi ,  assert: ↑b
Lemmas referenced :  Sierpinski-unequal-1,  Sierpinski_wf,  quotient-member-eq,  nat_wf,  bool_wf,  iff_wf,  equal-wf-T-base,  two-class-equiv-rel,  Sierpinski-bottom_wf,  eqtt_to_assert,  Sierpinski-top_wf,  equal-wf-base,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  bfalse_wf,  not_wf,  assert_elim,  btrue_neq_bfalse
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  productElimination,  thin,  isect_memberFormation,  lambdaFormation,  pointwiseFunctionalityForEquality,  hypothesis,  sqequalRule,  pertypeElimination,  isectElimination,  functionEquality,  lambdaEquality,  hypothesisEquality,  baseClosed,  because_Cache,  independent_isectElimination,  dependent_functionElimination,  equalityTransitivity,  equalitySymmetry,  independent_functionElimination,  independent_pairFormation,  functionExtensionality,  rename,  applyEquality,  unionElimination,  equalityElimination,  voidElimination,  dependent_pairFormation,  promote_hyp,  instantiate,  cumulativity,  productEquality,  axiomEquality,  applyLambdaEquality

Latex:
\mforall{}[x:Sierpinski].  ((\mneg{}(x  =  \mtop{}))  {}\mRightarrow{}  (x  =  \mbot{}))



Date html generated: 2019_10_31-AM-06_35_29
Last ObjectModification: 2017_07_28-AM-09_11_56

Theory : synthetic!topology


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