Nuprl Lemma : total-function-rational-approx

f:ℝ ⟶ ℝ. ∀y:ℝ.  ((∀x,y:ℝ.  ((x y)  (f[x] f[y])))  lim n→∞.f[(y within 1/n 1)] f[y])


Proof




Definitions occuring in Statement :  converges-to: lim n→∞.x[n] y rational-approx: (x within 1/n) req: y real: so_apply: x[s] all: x:A. B[x] implies:  Q function: x:A ⟶ B[x] add: m natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T implies:  Q so_lambda: λ2x.t[x] uall: [x:A]. B[x] real: nat_plus: + nat: le: A ≤ B and: P ∧ Q decidable: Dec(P) or: P ∨ Q iff: ⇐⇒ Q not: ¬A rev_implies:  Q false: False prop: uiff: uiff(P;Q) uimplies: supposing a subtract: m subtype_rel: A ⊆B top: Top less_than': less_than'(a;b) true: True so_apply: x[s]
Lemmas referenced :  total-function-limit rational-approx_wf decidable__lt false_wf not-lt-2 condition-implies-le minus-add minus-one-mul zero-add minus-one-mul-top add-commutes add_functionality_wrt_le add-associates add-zero le-add-cancel less_than_wf nat_wf rational-approx-converges-to all_wf real_wf req_wf
Rules used in proof :  cut introduction extract_by_obid sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation hypothesis sqequalHypSubstitution dependent_functionElimination thin hypothesisEquality sqequalRule lambdaEquality isectElimination setElimination rename because_Cache dependent_set_memberEquality addEquality natural_numberEquality productElimination unionElimination independent_pairFormation voidElimination independent_functionElimination independent_isectElimination applyEquality isect_memberEquality voidEquality intEquality minusEquality functionEquality functionExtensionality

Latex:
\mforall{}f:\mBbbR{}  {}\mrightarrow{}  \mBbbR{}.  \mforall{}y:\mBbbR{}.    ((\mforall{}x,y:\mBbbR{}.    ((x  =  y)  {}\mRightarrow{}  (f[x]  =  f[y])))  {}\mRightarrow{}  lim  n\mrightarrow{}\minfty{}.f[(y  within  1/n  +  1)]  =  f[y])



Date html generated: 2017_10_03-AM-10_21_53
Last ObjectModification: 2017_06_30-PM-04_15_10

Theory : reals


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