Nuprl Lemma : eu-length-flip

e:EuclideanPlane. ∀[a,b:Point].  (|ab| |ba| ∈ {p:Point| O_X_p} )


Proof




Definitions occuring in Statement :  eu-length: |s| eu-mk-seg: ab euclidean-plane: EuclideanPlane eu-between-eq: a_b_c eu-X: X eu-O: O eu-point: Point uall: [x:A]. B[x] all: x:A. B[x] set: {x:A| B[x]}  equal: t ∈ T
Definitions unfolded in proof :  all: x:A. B[x] uall: [x:A]. B[x] member: t ∈ T eu-length: |s| euclidean-plane: EuclideanPlane and: P ∧ Q prop: uiff: uiff(P;Q) uimplies: supposing a subtype_rel: A ⊆B
Lemmas referenced :  eu-extend-property eu-O_wf eu-not-colinear-OXY eu-X_wf not_wf equal_wf eu-point_wf eu-seg1_wf eu-mk-seg_wf eu-seg2_wf eu-between-eq_wf eu-seg-congruent-iff-length eu-congruent-flip-seg
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation isect_memberFormation introduction cut dependent_set_memberEquality sqequalRule lemma_by_obid sqequalHypSubstitution dependent_functionElimination thin because_Cache isectElimination setElimination rename hypothesisEquality hypothesis productElimination isect_memberEquality axiomEquality independent_isectElimination applyEquality

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}[a,b:Point].    (|ab|  =  |ba|)



Date html generated: 2016_05_18-AM-06_37_41
Last ObjectModification: 2015_12_28-AM-09_24_39

Theory : euclidean!geometry


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