Nuprl Lemma : ss-mem-open-and

[X:SeparationSpace]. ∀A,B:Open(X). ∀x:Point(X).  (x ∈ A ⋂ ⇐⇒ x ∈ A ∧ x ∈ B)


Proof




Definitions occuring in Statement :  ss-open-and: A ⋂ B ss-mem-open: x ∈ O ss-open: Open(X) ss-point: Point(ss) separation-space: SeparationSpace uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q implies:  Q ss-open-and: A ⋂ B ss-mem-open: x ∈ O exists: x:A. B[x] member: t ∈ T squash: T prop: true: True subtype_rel: A ⊆B uimplies: supposing a guard: {T} uiff: uiff(P;Q) ss-open: Open(X) rev_implies:  Q cand: c∧ B so_lambda: λ2x.t[x] so_apply: x[s] rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced :  ss-mem-basic_wf squash_wf true_wf ss-point_wf ss-basic_wf subtype_rel_self iff_weakening_equal ss-mem-basic-and ss-mem-open_wf ss-open-and_wf ss-basic-and_wf equal_wf exists_wf ss-open_wf separation-space_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation independent_pairFormation sqequalHypSubstitution sqequalRule productElimination thin cut applyEquality lambdaEquality imageElimination introduction extract_by_obid isectElimination hypothesisEquality equalityTransitivity hypothesis equalitySymmetry because_Cache natural_numberEquality imageMemberEquality baseClosed instantiate universeEquality independent_isectElimination independent_functionElimination dependent_functionElimination dependent_pairFormation productEquality rename

Latex:
\mforall{}[X:SeparationSpace].  \mforall{}A,B:Open(X).  \mforall{}x:Point(X).    (x  \mmember{}  A  \mcap{}  B  \mLeftarrow{}{}\mRightarrow{}  x  \mmember{}  A  \mwedge{}  x  \mmember{}  B)



Date html generated: 2020_05_20-PM-01_22_37
Last ObjectModification: 2018_07_06-PM-04_56_17

Theory : intuitionistic!topology


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