Nuprl Lemma : real-vec-angle-lemma

n:ℕ. ∀x,z:ℝ^n.  (d(z;x) < d(z;r(-1)*x) ⇐⇒ r0 < x⋅z)


Proof




Definitions occuring in Statement :  real-vec-dist: d(x;y) dot-product: x⋅y real-vec-mul: a*X real-vec: ^n rless: x < y int-to-real: r(n) nat: all: x:A. B[x] iff: ⇐⇒ Q minus: -n natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] real-vec-dist: d(x;y) real-vec-norm: ||x|| iff: ⇐⇒ Q and: P ∧ Q member: t ∈ T uall: [x:A]. B[x] prop: rev_implies:  Q implies:  Q subtype_rel: A ⊆B uimplies: supposing a uiff: uiff(P;Q) req_int_terms: t1 ≡ t2 false: False not: ¬A top: Top less_than: a < b squash: T less_than': less_than'(a;b) true: True
Lemmas referenced :  rsqrt-rless-iff dot-product-nonneg real-vec-sub_wf dot-product_wf rleq_wf int-to-real_wf real-vec-mul_wf rless_wf rsqrt_wf real_wf req_wf rmul_wf iff_wf real-vec_wf nat_wf dot-product-comm radd_wf rless_functionality rsub_wf itermSubtract_wf itermVar_wf itermAdd_wf itermMultiply_wf itermConstant_wf req-iff-rsub-is-0 req_transitivity dot-product-linearity1-sub rsub_functionality req_weakening dot-product-linearity2 rmul_functionality real_polynomial_null real_term_value_sub_lemma real_term_value_var_lemma real_term_value_add_lemma real_term_value_mul_lemma real_term_value_const_lemma radd-preserves-rless rmul_preserves_rless rless-int rmul-zero-both rmul_comm
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation cut addLevel sqequalHypSubstitution productElimination thin independent_pairFormation impliesFunctionality introduction extract_by_obid dependent_functionElimination isectElimination hypothesisEquality hypothesis dependent_set_memberEquality natural_numberEquality because_Cache minusEquality independent_functionElimination applyEquality sqequalRule lambdaEquality setElimination rename setEquality productEquality independent_isectElimination approximateComputation int_eqEquality intEquality isect_memberEquality voidElimination voidEquality imageMemberEquality baseClosed

Latex:
\mforall{}n:\mBbbN{}.  \mforall{}x,z:\mBbbR{}\^{}n.    (d(z;x)  <  d(z;r(-1)*x)  \mLeftarrow{}{}\mRightarrow{}  r0  <  x\mcdot{}z)



Date html generated: 2018_05_22-PM-02_25_51
Last ObjectModification: 2018_03_27-PM-10_36_41

Theory : reals


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