Nuprl Lemma : lattice-join-le

l:Lattice. ∀a,b,c:Point(l).  (a ∨ b ≤ ⇐⇒ a ≤ c ∧ b ≤ c)


Proof




Definitions occuring in Statement :  lattice-le: a ≤ b lattice: Lattice lattice-join: a ∨ b lattice-point: Point(l) all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T least-upper-bound: least-upper-bound(T;x,y.R[x; y];a;b;c) and: P ∧ Q iff: ⇐⇒ Q implies:  Q uall: [x:A]. B[x] lattice: Lattice rev_implies:  Q prop: guard: {T} uimplies: supposing a
Lemmas referenced :  lattice-le_transitivity lattice_wf lattice-point_wf and_wf lattice-join_wf lattice-le_wf lattice-join-is-lub
Rules used in proof :  cut lemma_by_obid sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation hypothesis sqequalHypSubstitution dependent_functionElimination thin hypothesisEquality productElimination independent_pairFormation isectElimination setElimination rename independent_functionElimination independent_isectElimination

Latex:
\mforall{}l:Lattice.  \mforall{}a,b,c:Point(l).    (a  \mvee{}  b  \mleq{}  c  \mLeftarrow{}{}\mRightarrow{}  a  \mleq{}  c  \mwedge{}  b  \mleq{}  c)



Date html generated: 2020_05_20-AM-08_25_41
Last ObjectModification: 2016_01_19-PM-02_35_04

Theory : lattices


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