Nuprl Lemma : setmem_functionality

∀x1,s1,x2,s2:coSet{i:l}.  (seteq(x1;x2) ⇒ seteq(s1;s2) ⇒ {(x1 ∈ s1) ⇐⇒ (x2 ∈ s2)})


Proof




Definitions occuring in Statement :  setmem: (x ∈ s),  seteq: seteq(s1;s2),  coSet: coSet{i:l},  guard: {T},  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  implies: P ⇒ Q
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  all: ∀x:A. B[x]
Lemmas referenced :  coSet_wf,  setmemfunc_wf
Rules used in proof :  because_Cache,  hypothesis,  hypothesisEquality,  thin,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  cut,  introduction,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution

Latex:
\mforall{}x1,s1,x2,s2:coSet\{i:l\}.    (seteq(x1;x2)  {}\mRightarrow{}  seteq(s1;s2)  {}\mRightarrow{}  \{(x1  \mmember{}  s1)  \mLeftarrow{}{}\mRightarrow{}  (x2  \mmember{}  s2)\})



Date html generated: 2018_07_29-AM-09_51_38
Last ObjectModification: 2018_07_11-PM-00_36_00

Theory : constructive!set!theory


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