Nuprl Lemma : can-find-first-ext

∀[T:Type]. ∀L:T List. ∀P:{x:T| (x ∈ L)}  ⟶ 𝔹.  ((∃x:T [first-member(T;x;L;P)]) ∨ (∀x∈L.¬↑(P x)))


Proof




Definitions occuring in Statement :  first-member: first-member(T;x;L;P),  l_all: (∀x∈L.P[x]),  l_member: (x ∈ l),  list: T List,  assert: ↑b,  bool: 𝔹,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  sq_exists: ∃x:A [B[x]],  not: ¬A,  or: P ∨ Q,  set: {x:A| B[x]} ,  apply: f a,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  member: t ∈ T,  ifthenelse: if b then t else f fi ,  subtract: n - m,  can-find-first2,  can-find-first1-ext
Lemmas referenced :  can-find-first2,  can-find-first1-ext
Rules used in proof :  introduction,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  cut,  instantiate,  extract_by_obid,  hypothesis,  sqequalRule,  thin,  sqequalHypSubstitution,  equalityTransitivity,  equalitySymmetry

Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  \mforall{}P:\{x:T|  (x  \mmember{}  L)\}    {}\mrightarrow{}  \mBbbB{}.    ((\mexists{}x:T  [first-member(T;x;L;P)])  \mvee{}  (\mforall{}x\mmember{}L.\mneg{}\muparrow{}(P  x)))



Date html generated: 2018_05_21-PM-06_34_45
Last ObjectModification: 2018_05_19-PM-04_41_05

Theory : general


Home Index