Nuprl Lemma : rsub-int-fractions
∀[a,b:ℤ]. ∀[c,d:ℕ+]. (((r(a)/r(c)) - (r(b)/r(d))) = (r((a * d) - b * c)/r(c * d)))
Proof
Definitions occuring in Statement :
rdiv: (x/y)
,
rsub: x - y
,
req: x = y
,
int-to-real: r(n)
,
nat_plus: ℕ+
,
uall: ∀[x:A]. B[x]
,
multiply: n * m
,
subtract: n - m
,
int: ℤ
Definitions unfolded in proof :
uall: ∀[x:A]. B[x]
,
member: t ∈ T
,
nat_plus: ℕ+
,
uimplies: b supposing a
,
rneq: x ≠ y
,
guard: {T}
,
or: P ∨ Q
,
all: ∀x:A. B[x]
,
iff: P
⇐⇒ Q
,
and: P ∧ Q
,
rev_implies: P
⇐ Q
,
implies: P
⇒ Q
,
decidable: Dec(P)
,
not: ¬A
,
satisfiable_int_formula: satisfiable_int_formula(fmla)
,
exists: ∃x:A. B[x]
,
false: False
,
prop: ℙ
,
true: True
,
subtract: n - m
,
squash: ↓T
,
subtype_rel: A ⊆r B
,
rsub: x - y
,
uiff: uiff(P;Q)
,
rev_uimplies: rev_uimplies(P;Q)
Latex:
\mforall{}[a,b:\mBbbZ{}]. \mforall{}[c,d:\mBbbN{}\msupplus{}]. (((r(a)/r(c)) - (r(b)/r(d))) = (r((a * d) - b * c)/r(c * d)))
Date html generated:
2020_05_20-AM-11_00_43
Last ObjectModification:
2020_01_03-AM-11_17_22
Theory : reals
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