Nuprl Lemma : vec-midpoint-dist

[n:ℕ]. ∀[a,b:ℝ^n].  (d(a;vec-midpoint(a;b)) ((r1/r(2)) d(a;b)))


Proof




Definitions occuring in Statement :  vec-midpoint: vec-midpoint(a;b) real-vec-dist: d(x;y) real-vec: ^n rdiv: (x/y) req: y rmul: b int-to-real: r(n) nat: uall: [x:A]. B[x] natural_number: $n
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a rneq: x ≠ y guard: {T} or: P ∨ Q all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q implies:  Q less_than: a < b squash: T less_than': less_than'(a;b) true: True prop: nat_plus: + nat: ge: i ≥  decidable: Dec(P) not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] top: Top false: False uiff: uiff(P;Q) le: A ≤ B subtype_rel: A ⊆B rev_uimplies: rev_uimplies(P;Q) real-vec-mul: a*X real-vec-sub: Y vec-midpoint: vec-midpoint(a;b) req-vec: req-vec(n;x;y) real-vec-add: Y int_seg: {i..j-} lelt: i ≤ j < k real-vec: ^n rat_term_to_real: rat_term_to_real(f;t) rtermSubtract: left "-" right rat_term_ind: rat_term_ind rtermMultiply: left "*" right rtermDivide: num "/" denom rtermConstant: "const" rtermVar: rtermVar(var) pi1: fst(t) rtermAdd: left "+" right pi2: snd(t)
Lemmas referenced :  rabs-of-nonneg rdiv_wf int-to-real_wf rless-int rless_wf rleq-int-fractions2 nat_properties decidable__lt full-omega-unsat intformnot_wf intformless_wf itermConstant_wf istype-int int_formula_prop_not_lemma istype-void int_formula_prop_less_lemma int_term_value_constant_lemma int_formula_prop_wf istype-less_than istype-false req_witness real-vec-dist_wf vec-midpoint_wf rmul_wf real-vec_wf istype-nat rabs_wf real-vec-mul_wf real-vec-dist-equal-iff req_functionality req_weakening rmul_functionality req_inversion real-vec-dist-dilation dot-product_wf real-vec-sub_wf dot-product-comm dot-product_functionality assert-rat-term-eq2 rtermSubtract_wf rtermVar_wf rtermMultiply_wf rtermDivide_wf rtermConstant_wf rtermAdd_wf int_seg_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut extract_by_obid sqequalHypSubstitution isectElimination thin closedConclusion natural_numberEquality hypothesis independent_isectElimination sqequalRule inrFormation_alt dependent_functionElimination because_Cache productElimination independent_functionElimination independent_pairFormation imageMemberEquality hypothesisEquality baseClosed universeIsType dependent_set_memberEquality_alt setElimination rename unionElimination approximateComputation dependent_pairFormation_alt lambdaEquality_alt isect_memberEquality_alt voidElimination lambdaFormation_alt applyEquality inhabitedIsType equalityTransitivity equalitySymmetry isectIsTypeImplies int_eqEquality

Latex:
\mforall{}[n:\mBbbN{}].  \mforall{}[a,b:\mBbbR{}\^{}n].    (d(a;vec-midpoint(a;b))  =  ((r1/r(2))  *  d(a;b)))



Date html generated: 2019_10_30-AM-11_32_26
Last ObjectModification: 2019_04_02-PM-04_09_01

Theory : reals!model!euclidean!geometry


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