Nuprl Lemma : isleft-symmetry

g:OrientedPlane. ∀a,b:Point. ∀c:{c:Point| bc} .  isleft(a;b;c) isleft(b;c;a)


Proof




Definitions occuring in Statement :  geo-isleft: isleft(a;b;c) oriented-plane: OrientedPlane geo-lsep: bc geo-point: Point bool: 𝔹 all: x:A. B[x] set: {x:A| B[x]}  equal: t ∈ T
Definitions unfolded in proof :  so_apply: x[s] so_lambda: λ2x.t[x] subtype_rel: A ⊆B rev_implies:  Q iff: ⇐⇒ Q uimplies: supposing a cand: c∧ B and: P ∧ Q guard: {T} implies:  Q prop: oriented-plane: Error :oriented-plane,  member: t ∈ T uall: [x:A]. B[x] all: x:A. B[x]
Lemmas referenced :  Error :basic-geo-primitives_wf,  Error :basic-geo-structure_wf,  basic-geometry-_wf Error :oriented-plane_wf,  subtype_rel_transitivity Error :oriented-plane-subtype,  basic-geometry--subtype geo-point_wf set_wf iff_wf assert_wf assert-geo-isleft geo-left_wf left-symmetry lsep-all-sym geo-lsep_wf geo-isleft_wf iff_imp_equal_bool
Rules used in proof :  lambdaEquality sqequalRule instantiate applyEquality impliesFunctionality addLevel independent_pairFormation independent_isectElimination productElimination independent_functionElimination dependent_functionElimination because_Cache dependent_set_memberEquality hypothesis hypothesisEquality rename setElimination thin isectElimination sqequalHypSubstitution extract_by_obid introduction cut lambdaFormation sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution

Latex:
\mforall{}g:OrientedPlane.  \mforall{}a,b:Point.  \mforall{}c:\{c:Point|  a  \#  bc\}  .    isleft(a;b;c)  =  isleft(b;c;a)



Date html generated: 2017_10_02-PM-06_50_20
Last ObjectModification: 2017_08_06-PM-07_30_17

Theory : euclidean!plane!geometry


Home Index