Nuprl Lemma : oob-getleft_wf

∀[B,A:Type]. ∀[x:{x:one_or_both(A;B)| ↑oob-hasleft(x)} ].  (oob-getleft(x) ∈ A)


Proof




Definitions occuring in Statement :  oob-getleft: oob-getleft(x),  oob-hasleft: oob-hasleft(x),  one_or_both: one_or_both(A;B),  assert: ↑b,  uall: ∀[x:A]. B[x],  member: t ∈ T,  set: {x:A| B[x]} ,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  oob-getleft: oob-getleft(x),  all: ∀x:A. B[x],  implies: P ⇒ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  ifthenelse: if b then t else f fi ,  bfalse: ff,  subtype_rel: A ⊆r B,  top: Top,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  oob-hasleft: oob-hasleft(x),  or: P ∨ Q,  not: ¬A,  false: False
Lemmas referenced :  oobleft?_wf,  bool_wf,  eqtt_to_assert,  oobleft-lval_wf,  uiff_transitivity,  equal-wf-T-base,  assert_wf,  bnot_wf,  not_wf,  eqff_to_assert,  assert_of_bnot,  pi1_wf_top,  oobboth-bval_wf,  top_wf,  oob-subtype,  equal_wf,  set_wf,  one_or_both_wf,  oob-hasleft_wf,  assert_of_bor,  oobboth?_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  setElimination,  thin,  rename,  sqequalRule,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  cumulativity,  hypothesisEquality,  hypothesis,  lambdaFormation,  unionElimination,  equalityElimination,  because_Cache,  productElimination,  independent_isectElimination,  equalityTransitivity,  equalitySymmetry,  baseClosed,  independent_functionElimination,  applyEquality,  lambdaEquality,  isect_memberEquality,  voidElimination,  voidEquality,  dependent_functionElimination,  axiomEquality,  universeEquality

Latex:
\mforall{}[B,A:Type].  \mforall{}[x:\{x:one\_or\_both(A;B)|  \muparrow{}oob-hasleft(x)\}  ].    (oob-getleft(x)  \mmember{}  A)



Date html generated: 2018_05_21-PM-08_00_02
Last ObjectModification: 2017_07_26-PM-05_36_53

Theory : general


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