Nuprl Lemma : inf-unique

∀[A:Set(ℝ)]. ∀[b,c:ℝ].  (inf(A) = b ⇒ inf(A) = c ⇒ (b = c))


Proof




Definitions occuring in Statement :  inf: inf(A) = b,  rset: Set(ℝ),  req: x = y,  real: ℝ,  uall: ∀[x:A]. B[x],  implies: P ⇒ Q
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  implies: P ⇒ Q,  and: P ∧ Q,  uimplies: b supposing a,  prop: ℙ,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  all: ∀x:A. B[x],  guard: {T},  inf: inf(A) = b,  lower-bound: lower-bound(A;b)
Lemmas referenced :  rleq_antisymmetry,  inf_wf,  req_witness,  real_wf,  rset_wf,  rleq_inf,  rset-member_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  lambdaFormation_alt,  independent_pairFormation,  sqequalHypSubstitution,  productElimination,  thin,  extract_by_obid,  isectElimination,  hypothesisEquality,  independent_isectElimination,  hypothesis,  universeIsType,  sqequalRule,  lambdaEquality_alt,  dependent_functionElimination,  independent_functionElimination,  functionIsTypeImplies,  inhabitedIsType,  isect_memberEquality_alt,  because_Cache,  isectIsTypeImplies

Latex:
\mforall{}[A:Set(\mBbbR{})].  \mforall{}[b,c:\mBbbR{}].    (inf(A)  =  b  {}\mRightarrow{}  inf(A)  =  c  {}\mRightarrow{}  (b  =  c))



Date html generated: 2019_10_29-AM-10_40_50
Last ObjectModification: 2019_04_17-PM-04_03_52

Theory : reals


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