Nuprl Lemma : sp-meet-is-top

∀[x,y:Sierpinski].  (x ∧ y = ⊤ ∈ Sierpinski ⇐⇒ (x = ⊤ ∈ Sierpinski) ∧ (y = ⊤ ∈ Sierpinski))


Proof




Definitions occuring in Statement :  sp-meet: f ∧ g,  Sierpinski: Sierpinski,  Sierpinski-top: ⊤,  uall: ∀[x:A]. B[x],  iff: P ⇐⇒ Q,  and: 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],  prop: ℙ,  rev_implies: P ⇐ Q,  sp-meet: f ∧ g,  cand: A c∧ B,  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  uimplies: b supposing a,  all: ∀x:A. B[x],  squash: ↓T,  true: True,  subtype_rel: A ⊆r B,  guard: {T},  Sierpinski-bottom: ⊥,  bfalse: ff,  band: p ∧b q,  ifthenelse: if b then t else f fi ,  so_lambda: λ2x.t[x],  so_apply: x[s],  top: Top,  false: False,  Sierpinski-top: ⊤,  btrue: tt,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  assert: ↑b,  nat: ℕ,  le: A ≤ B,  less_than': less_than'(a;b),  not: ¬A,  coded-pair: coded-pair(m),  code-pair: code-pair(a;b),  triangular-num: t(n),  tsqrt: tsqrt(n),  isqrt: isqrt(x),  integer-sqrt-ext,  genrec-ap: genrec-ap,  le_int: i ≤z j,  bnot: ¬bb,  lt_int: i <z j,  subtract: n - m
Lemmas referenced :  Sierpinski-unequal-1,  Sierpinski_wf,  equal-wf-base,  iff_wf,  equal-wf-T-base,  nat_wf,  bool_wf,  sp-meet_wf,  quotient-member-eq,  two-class-equiv-rel,  Sierpinski-bottom_wf,  equal_wf,  coded-pair_wf,  band_wf,  squash_wf,  true_wf,  iff_weakening_equal,  spread_to_pi12,  top_wf,  subtype_rel_product,  bfalse_wf,  member_wf,  band_ff_simp,  btrue_wf,  equal-Sierpinski-bottom,  code-pair_wf,  false_wf,  le_wf,  assert_of_bnot,  integer-sqrt-ext
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  productElimination,  thin,  isect_memberFormation,  independent_pairFormation,  lambdaFormation,  pointwiseFunctionalityForEquality,  hypothesis,  sqequalRule,  pertypeElimination,  productEquality,  isectElimination,  because_Cache,  hypothesisEquality,  equalityTransitivity,  equalitySymmetry,  baseClosed,  functionEquality,  equalityElimination,  independent_pairEquality,  lambdaEquality,  dependent_functionElimination,  axiomEquality,  isect_memberEquality,  independent_isectElimination,  independent_functionElimination,  applyEquality,  imageElimination,  equalityUniverse,  levelHypothesis,  spreadEquality,  functionExtensionality,  natural_numberEquality,  imageMemberEquality,  voidElimination,  voidEquality,  universeEquality,  dependent_set_memberEquality

Latex:
\mforall{}[x,y:Sierpinski].    (x  \mwedge{}  y  =  \mtop{}  \mLeftarrow{}{}\mRightarrow{}  (x  =  \mtop{})  \mwedge{}  (y  =  \mtop{}))



Date html generated: 2019_10_31-AM-06_35_51
Last ObjectModification: 2017_07_28-AM-09_12_00

Theory : synthetic!topology


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