Nuprl Lemma : geo-colinear-cons

e:BasicGeometry. ∀L:Point List. ∀A:Point.
  (geo-colinear-set(e; [A L]) ⇐⇒ geo-colinear-set(e; L) ∧ (∀B∈L.(∀C∈L.Colinear(A;B;C))))


Proof




Definitions occuring in Statement :  basic-geometry: BasicGeometry geo-colinear-set: geo-colinear-set(e; L) geo-colinear: Colinear(a;b;c) geo-point: Point l_all: (∀x∈L.P[x]) cons: [a b] list: List all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q
Definitions unfolded in proof :  rev_implies:  Q so_apply: x[s] basic-geometry: BasicGeometry so_lambda: λ2x.t[x] uimplies: supposing a guard: {T} subtype_rel: A ⊆B uall: [x:A]. B[x] prop: member: t ∈ T implies:  Q and: P ∧ Q iff: ⇐⇒ Q geo-colinear-set: geo-colinear-set(e; L) all: x:A. B[x] cand: c∧ B subtract: m cons: [a b] select: L[n] true: True squash: T less_than: a < b not: ¬A false: False less_than': less_than'(a;b) le: A ≤ B lelt: i ≤ j < k int_seg: {i..j-} top: Top l_all: (∀x∈L.P[x])
Lemmas referenced :  list_wf iff_wf l_all_cons geo-colinear_wf l_member_wf cons_wf Error :basic-geo-primitives_wf,  Error :basic-geo-structure_wf,  basic-geometry_wf subtype_rel_transitivity basic-geometry-subtype geo-point_wf l_all_wf2 l_all_functionality l_all_iff geo-colinear-same all_wf lelt_wf false_wf length_of_nil_lemma length_of_cons_lemma geo-colinear-is-colinear-set geo-colinear-permute
Rules used in proof :  independent_functionElimination impliesFunctionality addLevel dependent_functionElimination setEquality rename setElimination lambdaEquality because_Cache sqequalRule independent_isectElimination instantiate hypothesis applyEquality hypothesisEquality isectElimination extract_by_obid introduction productEquality thin productElimination sqequalHypSubstitution independent_pairFormation cut lambdaFormation sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution promote_hyp functionEquality levelHypothesis allFunctionality baseClosed imageMemberEquality natural_numberEquality dependent_set_memberEquality voidEquality voidElimination isect_memberEquality

Latex:
\mforall{}e:BasicGeometry.  \mforall{}L:Point  List.  \mforall{}A:Point.
    (geo-colinear-set(e;  [A  /  L])  \mLeftarrow{}{}\mRightarrow{}  geo-colinear-set(e;  L)  \mwedge{}  (\mforall{}B\mmember{}L.(\mforall{}C\mmember{}L.Colinear(A;B;C))))



Date html generated: 2017_10_02-PM-06_20_21
Last ObjectModification: 2017_08_05-PM-04_14_46

Theory : euclidean!plane!geometry


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