Nuprl Lemma : weak-antecedent-surjection_functionality_wrt_pred_equiv

es:EO
  ∀[P1,P2,Q1,Q2:E ─→ ℙ].  ∀f:{e:E| P1 e}  ─→ {e:E| Q1 e} (P1 ⇐⇒ P2  Q1 ⇐⇒ Q2  (Q1 ←←f== P1 ⇐⇒ Q2 ←←f== P2))


Proof




Definitions occuring in Statement :  weak-antecedent-surjection: Q ←←f== P es-E: E event_ordering: EO predicate_equivalent: P1 ⇐⇒ P2 uall: [x:A]. B[x] prop: all: x:A. B[x] iff: ⇐⇒ Q implies:  Q set: {x:A| B[x]}  apply: a function: x:A ─→ B[x]
Lemmas :  subtype_rel_sets equal_wf set_wf weak-antecedent-surjection_wf subtype_rel_dep_function es-E_wf all_wf iff_wf event_ordering_wf
\mforall{}es:EO
    \mforall{}[P1,P2,Q1,Q2:E  {}\mrightarrow{}  \mBbbP{}].
        \mforall{}f:\{e:E|  P1  e\}    {}\mrightarrow{}  \{e:E|  Q1  e\}  .  (P1  \mLeftarrow{}{}\mRightarrow{}  P2  {}\mRightarrow{}  Q1  \mLeftarrow{}{}\mRightarrow{}  Q2  {}\mRightarrow{}  (Q1  \mleftarrow{}\mleftarrow{}=  f==  P1  \mLeftarrow{}{}\mRightarrow{}  Q2  \mleftarrow{}\mleftarrow{}=  f==  P2))



Date html generated: 2015_07_17-AM-09_02_28
Last ObjectModification: 2015_01_27-PM-00_55_44

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