Nuprl Lemma : ratreal-ratsub

[a,b:ℤ × ℕ+].  (ratreal(ratsub(a;b)) (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] product: x:A × B[x] int:
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T subtype_rel: A ⊆B sq_stable: SqStable(P) implies:  Q all: x:A. B[x] squash: T
Lemmas referenced :  sq_stable__req ratreal_wf ratsub_wf rsub_wf istype-int nat_plus_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis applyEquality lambdaEquality_alt setElimination rename inhabitedIsType equalityTransitivity equalitySymmetry sqequalRule independent_functionElimination lambdaFormation_alt because_Cache imageMemberEquality baseClosed imageElimination equalityIstype dependent_functionElimination productIsType universeIsType

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



Date html generated: 2019_10_30-AM-09_25_54
Last ObjectModification: 2019_01_11-PM-00_24_49

Theory : reals


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