Nuprl Lemma : setsubset-iff

a,b:coSet{i:l}.  ((a ⊆ b) ⇐⇒ ∀x:coSet{i:l}. ((x ∈ a)  (x ∈ b)))


Proof




Definitions occuring in Statement :  setsubset: (a ⊆ b) setmem: (x ∈ s) coSet: coSet{i:l} all: x:A. B[x] iff: ⇐⇒ Q implies:  Q
Definitions unfolded in proof :  guard: {T} set-predicate: set-predicate{i:l}(s;a.P[a]) rev_implies:  Q so_apply: x[s] so_lambda: λ2x.t[x] uall: [x:A]. B[x] prop: member: t ∈ T implies:  Q and: P ∧ Q iff: ⇐⇒ Q setsubset: (a ⊆ b) all: x:A. B[x]
Lemmas referenced :  iff_wf allsetmem_wf seteq_wf setmem_functionality_1 allsetmem-iff coSet_wf all_wf setmem_wf
Rules used in proof :  independent_functionElimination setEquality rename setElimination dependent_functionElimination impliesFunctionality productElimination addLevel functionEquality 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\}.    ((a  \msubseteq{}  b)  \mLeftarrow{}{}\mRightarrow{}  \mforall{}x:coSet\{i:l\}.  ((x  \mmember{}  a)  {}\mRightarrow{}  (x  \mmember{}  b)))



Date html generated: 2018_07_29-AM-10_01_14
Last ObjectModification: 2018_07_20-PM-06_23_45

Theory : constructive!set!theory


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