Nuprl Lemma : all-accessible-iff-weak-TI

∀[T:Type]. ∀[R:T ⟶ T ⟶ ℙ].  (∀t:T. accessible(T;x,y.R[x;y];t) ⇐⇒ ∀[P:T ⟶ ℙ]. weak-TI(T;x,y.R[y;x];t.P[t]))


Proof




Definitions occuring in Statement :  accessible: accessible(T;x,y.R[x; y];t),  weak-TI: weak-TI(T;x,y.R[x; y];t.Q[t]),  uall: ∀[x:A]. B[x],  prop: ℙ,  so_apply: x[s1;s2],  so_apply: x[s],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  weak-TI: weak-TI(T;x,y.R[x; y];t.Q[t])
Lemmas referenced :  all-accessible-iff-induction
Rules used in proof :  cut,  lemma_by_obid,  sqequalHypSubstitution,  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  hypothesis

Latex:
\mforall{}[T:Type].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    (\mforall{}t:T.  accessible(T;x,y.R[x;y];t)  \mLeftarrow{}{}\mRightarrow{}  \mforall{}[P:T  {}\mrightarrow{}  \mBbbP{}].  weak-TI(T;x,y.R[y;x];t.P[t]))



Date html generated: 2016_05_14-AM-06_18_52
Last ObjectModification: 2015_12_26-PM-00_02_41

Theory : co-recursion


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