Nuprl Lemma : seteq-iff-setsubset

a,b:coSet{i:l}.  (seteq(a;b) ⇐⇒ (a ⊆ b) ∧ (b ⊆ a))


Proof




Definitions occuring in Statement :  setsubset: (a ⊆ b) seteq: seteq(s1;s2) coSet: coSet{i:l} all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q
Definitions unfolded in proof :  guard: {T} so_apply: x[s] rev_implies:  Q so_lambda: λ2x.t[x] uall: [x:A]. B[x] prop: member: t ∈ T implies:  Q and: P ∧ Q iff: ⇐⇒ Q all: x:A. B[x]
Lemmas referenced :  setsubset_wf seteq_wf setsubset-iff co-seteq-iff iff_wf coSet_wf all_wf setmem_wf
Rules used in proof :  andLevelFunctionality independent_functionElimination dependent_functionElimination impliesFunctionality addLevel functionEquality productEquality productElimination cumulativity lambdaEquality sqequalRule instantiate because_Cache hypothesis hypothesisEquality thin isectElimination sqequalHypSubstitution extract_by_obid introduction independent_pairFormation cut lambdaFormation sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution

Latex:
\mforall{}a,b:coSet\{i:l\}.    (seteq(a;b)  \mLeftarrow{}{}\mRightarrow{}  (a  \msubseteq{}  b)  \mwedge{}  (b  \msubseteq{}  a))



Date html generated: 2018_07_29-AM-10_01_24
Last ObjectModification: 2018_07_18-PM-01_30_00

Theory : constructive!set!theory


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