Nuprl Lemma : ratsub_wf

[a,b:ℤ × ℕ+].  (ratsub(a;b) ∈ {r:ℤ × ℕ+ratreal(r) (ratreal(a) ratreal(b))} )


Proof




Definitions occuring in Statement :  ratsub: ratsub(x;y) ratreal: ratreal(r) rsub: y req: y nat_plus: + uall: [x:A]. B[x] member: t ∈ T set: {x:A| B[x]}  product: x:A × B[x] int:
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T ratsub: ratsub(x;y) subtype_rel: A ⊆B prop: uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a rev_uimplies: rev_uimplies(P;Q) all: x:A. B[x] req_int_terms: t1 ≡ t2 false: False implies:  Q not: ¬A top: Top
Lemmas referenced :  istype-int nat_plus_wf ratadd_wf int-rat-mul_wf req_wf ratreal_wf rsub_wf radd_wf rmul_wf int-to-real_wf int-rmul_wf itermSubtract_wf itermAdd_wf itermVar_wf itermMultiply_wf itermConstant_wf req-iff-rsub-is-0 req_functionality req_transitivity ratreal-ratadd radd_functionality ratreal-int-rat-mul int-rmul-req req_weakening real_polynomial_null real_term_value_sub_lemma istype-void real_term_value_add_lemma real_term_value_var_lemma real_term_value_mul_lemma real_term_value_const_lemma
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut sqequalRule sqequalHypSubstitution hypothesis axiomEquality equalityTransitivity equalitySymmetry inhabitedIsType hypothesisEquality isect_memberEquality_alt isectElimination thin isectIsTypeImplies productIsType extract_by_obid universeIsType dependent_set_memberEquality_alt minusEquality natural_numberEquality applyEquality lambdaEquality_alt setElimination rename because_Cache productElimination independent_isectElimination dependent_functionElimination approximateComputation int_eqEquality voidElimination

Latex:
\mforall{}[a,b:\mBbbZ{}  \mtimes{}  \mBbbN{}\msupplus{}].    (ratsub(a;b)  \mmember{}  \{r:\mBbbZ{}  \mtimes{}  \mBbbN{}\msupplus{}|  ratreal(r)  =  (ratreal(a)  -  ratreal(b))\}  )



Date html generated: 2019_10_30-AM-09_25_22
Last ObjectModification: 2019_01_11-PM-00_22_42

Theory : reals


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