Structure ieeeTheory
signature ieeeTheory =
sig
type thm = Thm.thm
(* Definitions *)
val Exponent : thm
val Finite : thm
val Float : thm
val Fraction : thm
val Infinity : thm
val Isdenormal : thm
val Isintegral : thm
val Isnan : thm
val Isnormal : thm
val Iszero : thm
val Minus_infinity : thm
val Minus_zero : thm
val Plus_infinity : thm
val Plus_zero : thm
val ROUNDFLOAT : thm
val Sign : thm
val Ulp : thm
val Val : thm
val bias : thm
val bottomfloat : thm
val ccode_BIJ : thm
val ccode_CASE : thm
val ccode_TY_DEF : thm
val ccode_size_def : thm
val closest : thm
val emax : thm
val encoding : thm
val exponent : thm
val expwidth : thm
val fadd : thm
val fcompare : thm
val fdiv : thm
val feq : thm
val fge : thm
val fgt : thm
val fintrnd : thm
val fle : thm
val float_TY_DEF : thm
val float_abs : thm
val float_add : thm
val float_div : thm
val float_eq : thm
val float_format : thm
val float_ge : thm
val float_gt : thm
val float_le : thm
val float_lt : thm
val float_mul : thm
val float_neg : thm
val float_rem : thm
val float_sqrt : thm
val float_sub : thm
val float_tybij : thm
val flt : thm
val fmul : thm
val fneg : thm
val fraction : thm
val fracwidth : thm
val frem : thm
val fsqrt : thm
val fsub : thm
val intround_def : thm
val is_closest : thm
val is_denormal : thm
val is_double : thm
val is_double_extended : thm
val is_finite : thm
val is_infinity : thm
val is_integral : thm
val is_nan : thm
val is_normal : thm
val is_single : thm
val is_single_extended : thm
val is_valid : thm
val is_zero : thm
val largest : thm
val minus : thm
val minus_infinity : thm
val minus_zero : thm
val plus_infinity : thm
val plus_zero : thm
val rem : thm
val round_def : thm
val roundmode_BIJ : thm
val roundmode_CASE : thm
val roundmode_TY_DEF : thm
val roundmode_size_def : thm
val sign : thm
val some_nan : thm
val threshold : thm
val topfloat : thm
val ulp : thm
val valof : thm
val wordlength : thm
val zerosign : thm
(* Theorems *)
val ccode2num_11 : thm
val ccode2num_ONTO : thm
val ccode2num_num2ccode : thm
val ccode2num_thm : thm
val ccode_Axiom : thm
val ccode_EQ_ccode : thm
val ccode_case_cong : thm
val ccode_case_def : thm
val ccode_distinct : thm
val ccode_induction : thm
val ccode_nchotomy : thm
val datatype_ccode : thm
val datatype_roundmode : thm
val num2ccode_11 : thm
val num2ccode_ONTO : thm
val num2ccode_ccode2num : thm
val num2ccode_thm : thm
val num2roundmode_11 : thm
val num2roundmode_ONTO : thm
val num2roundmode_roundmode2num : thm
val num2roundmode_thm : thm
val roundmode2num_11 : thm
val roundmode2num_ONTO : thm
val roundmode2num_num2roundmode : thm
val roundmode2num_thm : thm
val roundmode_Axiom : thm
val roundmode_EQ_roundmode : thm
val roundmode_case_cong : thm
val roundmode_case_def : thm
val roundmode_distinct : thm
val roundmode_induction : thm
val roundmode_nchotomy : thm
val ieee_grammars : type_grammar.grammar * term_grammar.grammar
(*
[transc] Parent theory of "ieee"
[Exponent] Definition
|- ∀a. Exponent a = exponent (defloat a)
[Finite] Definition
|- ∀a. Finite a ⇔ Isnormal a ∨ Isdenormal a ∨ Iszero a
[Float] Definition
|- ∀x. Float x = float (round float_format To_nearest x)
[Fraction] Definition
|- ∀a. Fraction a = fraction (defloat a)
[Infinity] Definition
|- ∀a. Infinity a ⇔ is_infinity float_format (defloat a)
[Isdenormal] Definition
|- ∀a. Isdenormal a ⇔ is_denormal float_format (defloat a)
[Isintegral] Definition
|- ∀a. Isintegral a ⇔ is_integral float_format (defloat a)
[Isnan] Definition
|- ∀a. Isnan a ⇔ is_nan float_format (defloat a)
[Isnormal] Definition
|- ∀a. Isnormal a ⇔ is_normal float_format (defloat a)
[Iszero] Definition
|- ∀a. Iszero a ⇔ is_zero float_format (defloat a)
[Minus_infinity] Definition
|- Minus_infinity = float (minus_infinity float_format)
[Minus_zero] Definition
|- Minus_zero = float (minus_zero float_format)
[Plus_infinity] Definition
|- Plus_infinity = float (plus_infinity float_format)
[Plus_zero] Definition
|- Plus_zero = float (plus_zero float_format)
[ROUNDFLOAT] Definition
|- ∀a.
ROUNDFLOAT a =
float (fintrnd float_format To_nearest (defloat a))
[Sign] Definition
|- ∀a. Sign a = sign (defloat a)
[Ulp] Definition
|- ∀a. Ulp a = ulp float_format (defloat a)
[Val] Definition
|- ∀a. Val a = valof float_format (defloat a)
[bias] Definition
|- ∀X. bias X = 2 ** (expwidth X − 1) − 1
[bottomfloat] Definition
|- ∀X. bottomfloat X = (1,emax X − 1,2 ** fracwidth X − 1)
[ccode_BIJ] Definition
|- (∀a. num2ccode (ccode2num a) = a) ∧
∀r. (λn. n < 4) r ⇔ (ccode2num (num2ccode r) = r)
[ccode_CASE] Definition
|- ∀x v0 v1 v2 v3.
(case x of Gt => v0 | Lt => v1 | Eq => v2 | Un => v3) =
(λm.
if m < 1 then v0
else if m < 2 then v1
else if m = 2 then v2
else v3) (ccode2num x)
[ccode_TY_DEF] Definition
|- ∃rep. TYPE_DEFINITION (λn. n < 4) rep
[ccode_size_def] Definition
|- ∀x. ccode_size x = 0
[closest] Definition
|- ∀v p s x.
closest v p s x =
@a. is_closest v s x a ∧ ((∃b. is_closest v s x b ∧ p b) ⇒ p a)
[emax] Definition
|- ∀X. emax X = 2 ** expwidth X − 1
[encoding] Definition
|- ∀X s e f.
encoding X (s,e,f) =
s * 2 ** (wordlength X − 1) + e * 2 ** fracwidth X + f
[exponent] Definition
|- ∀s e f. exponent (s,e,f) = e
[expwidth] Definition
|- ∀ew fw. expwidth (ew,fw) = ew
[fadd] Definition
|- ∀X m a b.
fadd X m a b =
if
is_nan X a ∨ is_nan X b ∨
is_infinity X a ∧ is_infinity X b ∧ sign a ≠ sign b
then
some_nan X
else if is_infinity X a then a
else if is_infinity X b then b
else
zerosign X
(if is_zero X a ∧ is_zero X b ∧ (sign a = sign b) then
sign a
else if m = To_ninfinity then 1
else 0) (round X m (valof X a + valof X b))
[fcompare] Definition
|- ∀X a b.
fcompare X a b =
if is_nan X a ∨ is_nan X b then Un
else if is_infinity X a ∧ (sign a = 1) then
if is_infinity X b ∧ (sign b = 1) then Eq else Lt
else if is_infinity X a ∧ (sign a = 0) then
if is_infinity X b ∧ (sign b = 0) then Eq else Gt
else if is_infinity X b ∧ (sign b = 1) then Gt
else if is_infinity X b ∧ (sign b = 0) then Lt
else if valof X a < valof X b then Lt
else if valof X a = valof X b then Eq
else Gt
[fdiv] Definition
|- ∀X m a b.
fdiv X m a b =
if
is_nan X a ∨ is_nan X b ∨ is_zero X a ∧ is_zero X b ∨
is_infinity X a ∧ is_infinity X b
then
some_nan X
else if is_infinity X a ∨ is_zero X b then
if sign a = sign b then plus_infinity X else minus_infinity X
else if is_infinity X b then
if sign a = sign b then plus_zero X else minus_zero X
else
zerosign X (if sign a = sign b then 0 else 1)
(round X m (valof X a / valof X b))
[feq] Definition
|- ∀X a b. feq X a b ⇔ (fcompare X a b = Eq)
[fge] Definition
|- ∀X a b. fge X a b ⇔ (fcompare X a b = Gt) ∨ (fcompare X a b = Eq)
[fgt] Definition
|- ∀X a b. fgt X a b ⇔ (fcompare X a b = Gt)
[fintrnd] Definition
|- ∀X m a.
fintrnd X m a =
if is_nan X a then some_nan X
else if is_infinity X a then a
else zerosign X (sign a) (intround X m (valof X a))
[fle] Definition
|- ∀X a b. fle X a b ⇔ (fcompare X a b = Lt) ∨ (fcompare X a b = Eq)
[float_TY_DEF] Definition
|- ∃rep. TYPE_DEFINITION (is_valid float_format) rep
[float_abs] Definition
|- ∀a. float_abs a = if a ≥ Plus_zero then a else ¬a
[float_add] Definition
|- ∀a b.
a + b =
float (fadd float_format To_nearest (defloat a) (defloat b))
[float_div] Definition
|- ∀a b.
a / b =
float (fdiv float_format To_nearest (defloat a) (defloat b))
[float_eq] Definition
|- ∀a b. a == b ⇔ feq float_format (defloat a) (defloat b)
[float_format] Definition
|- float_format = (8,23)
[float_ge] Definition
|- ∀a b. a ≥ b ⇔ fge float_format (defloat a) (defloat b)
[float_gt] Definition
|- ∀a b. a > b ⇔ fgt float_format (defloat a) (defloat b)
[float_le] Definition
|- ∀a b. a ≤ b ⇔ fle float_format (defloat a) (defloat b)
[float_lt] Definition
|- ∀a b. a < b ⇔ flt float_format (defloat a) (defloat b)
[float_mul] Definition
|- ∀a b.
a * b =
float (fmul float_format To_nearest (defloat a) (defloat b))
[float_neg] Definition
|- ∀a. ¬a = float (fneg float_format To_nearest (defloat a))
[float_rem] Definition
|- ∀a b.
a float_rem b =
float (frem float_format To_nearest (defloat a) (defloat b))
[float_sqrt] Definition
|- ∀a.
float_sqrt a = float (fsqrt float_format To_nearest (defloat a))
[float_sub] Definition
|- ∀a b.
a − b =
float (fsub float_format To_nearest (defloat a) (defloat b))
[float_tybij] Definition
|- (∀a. float (defloat a) = a) ∧
∀r. is_valid float_format r ⇔ (defloat (float r) = r)
[flt] Definition
|- ∀X a b. flt X a b ⇔ (fcompare X a b = Lt)
[fmul] Definition
|- ∀X m a b.
fmul X m a b =
if
is_nan X a ∨ is_nan X b ∨ is_zero X a ∧ is_infinity X b ∨
is_infinity X a ∧ is_zero X b
then
some_nan X
else if is_infinity X a ∨ is_infinity X b then
if sign a = sign b then plus_infinity X else minus_infinity X
else
zerosign X (if sign a = sign b then 0 else 1)
(round X m (valof X a * valof X b))
[fneg] Definition
|- ∀X m a. fneg X m a = (1 − sign a,exponent a,fraction a)
[fraction] Definition
|- ∀s e f. fraction (s,e,f) = f
[fracwidth] Definition
|- ∀ew fw. fracwidth (ew,fw) = fw
[frem] Definition
|- ∀X m a b.
frem X m a b =
if is_nan X a ∨ is_nan X b ∨ is_infinity X a ∨ is_zero X b then
some_nan X
else if is_infinity X b then a
else zerosign X (sign a) (round X m (valof X a rem valof X b))
[fsqrt] Definition
|- ∀X m a.
fsqrt X m a =
if is_nan X a then some_nan X
else if is_zero X a ∨ is_infinity X a ∧ (sign a = 0) then a
else if sign a = 1 then some_nan X
else zerosign X (sign a) (round X m (sqrt (valof X a)))
[fsub] Definition
|- ∀X m a b.
fsub X m a b =
if
is_nan X a ∨ is_nan X b ∨
is_infinity X a ∧ is_infinity X b ∧ (sign a = sign b)
then
some_nan X
else if is_infinity X a then a
else if is_infinity X b then minus X b
else
zerosign X
(if is_zero X a ∧ is_zero X b ∧ sign a ≠ sign b then sign a
else if m = To_ninfinity then 1
else 0) (round X m (valof X a − valof X b))
[intround_def] Definition
|- (∀X x.
intround X To_nearest x =
if x ≤ -threshold X then minus_infinity X
else if x ≥ threshold X then plus_infinity X
else
closest (valof X) (λa. ∃n. EVEN n ∧ (abs (valof X a) = &n))
{a | is_integral X a} x) ∧
(∀X x.
intround X float_To_zero x =
if x < -largest X then bottomfloat X
else if x > largest X then topfloat X
else
closest (valof X) (λx. T)
{a | is_integral X a ∧ abs (valof X a) ≤ abs x} x) ∧
(∀X x.
intround X To_pinfinity x =
if x < -largest X then bottomfloat X
else if x > largest X then plus_infinity X
else
closest (valof X) (λx. T)
{a | is_integral X a ∧ valof X a ≥ x} x) ∧
∀X x.
intround X To_ninfinity x =
if x < -largest X then minus_infinity X
else if x > largest X then topfloat X
else
closest (valof X) (λx. T)
{a | is_integral X a ∧ valof X a ≤ x} x
[is_closest] Definition
|- ∀v s x a.
is_closest v s x a ⇔
a ∈ s ∧ ∀b. b ∈ s ⇒ abs (v a − x) ≤ abs (v b − x)
[is_denormal] Definition
|- ∀X a. is_denormal X a ⇔ (exponent a = 0) ∧ fraction a ≠ 0
[is_double] Definition
|- ∀X. is_double X ⇔ (expwidth X = 11) ∧ (wordlength X = 64)
[is_double_extended] Definition
|- ∀X. is_double_extended X ⇔ expwidth X ≥ 15 ∧ wordlength X ≥ 79
[is_finite] Definition
|- ∀X a.
is_finite X a ⇔
is_valid X a ∧ (is_normal X a ∨ is_denormal X a ∨ is_zero X a)
[is_infinity] Definition
|- ∀X a. is_infinity X a ⇔ (exponent a = emax X) ∧ (fraction a = 0)
[is_integral] Definition
|- ∀X a. is_integral X a ⇔ is_finite X a ∧ ∃n. abs (valof X a) = &n
[is_nan] Definition
|- ∀X a. is_nan X a ⇔ (exponent a = emax X) ∧ fraction a ≠ 0
[is_normal] Definition
|- ∀X a. is_normal X a ⇔ 0 < exponent a ∧ exponent a < emax X
[is_single] Definition
|- ∀X. is_single X ⇔ (expwidth X = 8) ∧ (wordlength X = 32)
[is_single_extended] Definition
|- ∀X. is_single_extended X ⇔ expwidth X ≥ 11 ∧ wordlength X ≥ 43
[is_valid] Definition
|- ∀X s e f.
is_valid X (s,e,f) ⇔
s < SUC (SUC 0) ∧ e < 2 ** expwidth X ∧ f < 2 ** fracwidth X
[is_zero] Definition
|- ∀X a. is_zero X a ⇔ (exponent a = 0) ∧ (fraction a = 0)
[largest] Definition
|- ∀X.
largest X =
2 pow (emax X − 1) / 2 pow bias X *
(2 − inv (2 pow fracwidth X))
[minus] Definition
|- ∀X a. minus X a = (1 − sign a,exponent a,fraction a)
[minus_infinity] Definition
|- ∀X. minus_infinity X = (1,emax X,0)
[minus_zero] Definition
|- ∀X. minus_zero X = (1,0,0)
[plus_infinity] Definition
|- ∀X. plus_infinity X = (0,emax X,0)
[plus_zero] Definition
|- ∀X. plus_zero X = (0,0,0)
[rem] Definition
|- ∀x y.
x rem y =
(let n =
closest I (λx. ∃n. EVEN n ∧ (abs x = &n))
{x | ∃n. abs x = &n} (x / y)
in
x − n * y)
[round_def] Definition
|- (∀X x.
round X To_nearest x =
if x ≤ -threshold X then minus_infinity X
else if x ≥ threshold X then plus_infinity X
else
closest (valof X) (λa. EVEN (fraction a)) {a | is_finite X a}
x) ∧
(∀X x.
round X float_To_zero x =
if x < -largest X then bottomfloat X
else if x > largest X then topfloat X
else
closest (valof X) (λx. T)
{a | is_finite X a ∧ abs (valof X a) ≤ abs x} x) ∧
(∀X x.
round X To_pinfinity x =
if x < -largest X then bottomfloat X
else if x > largest X then plus_infinity X
else
closest (valof X) (λx. T) {a | is_finite X a ∧ valof X a ≥ x}
x) ∧
∀X x.
round X To_ninfinity x =
if x < -largest X then minus_infinity X
else if x > largest X then topfloat X
else
closest (valof X) (λx. T) {a | is_finite X a ∧ valof X a ≤ x}
x
[roundmode_BIJ] Definition
|- (∀a. num2roundmode (roundmode2num a) = a) ∧
∀r. (λn. n < 4) r ⇔ (roundmode2num (num2roundmode r) = r)
[roundmode_CASE] Definition
|- ∀x v0 v1 v2 v3.
(case x of
To_nearest => v0
| float_To_zero => v1
| To_pinfinity => v2
| To_ninfinity => v3) =
(λm.
if m < 1 then v0
else if m < 2 then v1
else if m = 2 then v2
else v3) (roundmode2num x)
[roundmode_TY_DEF] Definition
|- ∃rep. TYPE_DEFINITION (λn. n < 4) rep
[roundmode_size_def] Definition
|- ∀x. roundmode_size x = 0
[sign] Definition
|- ∀s e f. sign (s,e,f) = s
[some_nan] Definition
|- ∀X. some_nan X = @a. is_nan X a
[threshold] Definition
|- ∀X.
threshold X =
2 pow (emax X − 1) / 2 pow bias X *
(2 − inv (2 pow SUC (fracwidth X)))
[topfloat] Definition
|- ∀X. topfloat X = (0,emax X − 1,2 ** fracwidth X − 1)
[ulp] Definition
|- ∀X a.
ulp X a = valof X (0,exponent a,1) − valof X (0,exponent a,0)
[valof] Definition
|- ∀X s e f.
valof X (s,e,f) =
if e = 0 then
-1 pow s * (2 / 2 pow bias X) * (&f / 2 pow fracwidth X)
else
-1 pow s * (2 pow e / 2 pow bias X) *
(1 + &f / 2 pow fracwidth X)
[wordlength] Definition
|- ∀X. wordlength X = expwidth X + fracwidth X + 1
[zerosign] Definition
|- ∀X s a.
zerosign X s a =
if is_zero X a then if s = 0 then plus_zero X else minus_zero X
else a
[ccode2num_11] Theorem
|- ∀a a'. (ccode2num a = ccode2num a') ⇔ (a = a')
[ccode2num_ONTO] Theorem
|- ∀r. r < 4 ⇔ ∃a. r = ccode2num a
[ccode2num_num2ccode] Theorem
|- ∀r. r < 4 ⇔ (ccode2num (num2ccode r) = r)
[ccode2num_thm] Theorem
|- (ccode2num Gt = 0) ∧ (ccode2num Lt = 1) ∧ (ccode2num Eq = 2) ∧
(ccode2num Un = 3)
[ccode_Axiom] Theorem
|- ∀x0 x1 x2 x3.
∃f. (f Gt = x0) ∧ (f Lt = x1) ∧ (f Eq = x2) ∧ (f Un = x3)
[ccode_EQ_ccode] Theorem
|- ∀a a'. (a = a') ⇔ (ccode2num a = ccode2num a')
[ccode_case_cong] Theorem
|- ∀M M' v0 v1 v2 v3.
(M = M') ∧ ((M' = Gt) ⇒ (v0 = v0')) ∧ ((M' = Lt) ⇒ (v1 = v1')) ∧
((M' = Eq) ⇒ (v2 = v2')) ∧ ((M' = Un) ⇒ (v3 = v3')) ⇒
((case M of Gt => v0 | Lt => v1 | Eq => v2 | Un => v3) =
case M' of Gt => v0' | Lt => v1' | Eq => v2' | Un => v3')
[ccode_case_def] Theorem
|- (∀v0 v1 v2 v3.
(case Gt of Gt => v0 | Lt => v1 | Eq => v2 | Un => v3) = v0) ∧
(∀v0 v1 v2 v3.
(case Lt of Gt => v0 | Lt => v1 | Eq => v2 | Un => v3) = v1) ∧
(∀v0 v1 v2 v3.
(case Eq of Gt => v0 | Lt => v1 | Eq => v2 | Un => v3) = v2) ∧
∀v0 v1 v2 v3.
(case Un of Gt => v0 | Lt => v1 | Eq => v2 | Un => v3) = v3
[ccode_distinct] Theorem
|- Gt ≠ Lt ∧ Gt ≠ Eq ∧ Gt ≠ Un ∧ Lt ≠ Eq ∧ Lt ≠ Un ∧ Eq ≠ Un
[ccode_induction] Theorem
|- ∀P. P Eq ∧ P Gt ∧ P Lt ∧ P Un ⇒ ∀a. P a
[ccode_nchotomy] Theorem
|- ∀a. (a = Gt) ∨ (a = Lt) ∨ (a = Eq) ∨ (a = Un)
[datatype_ccode] Theorem
|- DATATYPE (ccode Gt Lt Eq Un)
[datatype_roundmode] Theorem
|- DATATYPE
(roundmode To_nearest float_To_zero To_pinfinity To_ninfinity)
[num2ccode_11] Theorem
|- ∀r r'. r < 4 ⇒ r' < 4 ⇒ ((num2ccode r = num2ccode r') ⇔ (r = r'))
[num2ccode_ONTO] Theorem
|- ∀a. ∃r. (a = num2ccode r) ∧ r < 4
[num2ccode_ccode2num] Theorem
|- ∀a. num2ccode (ccode2num a) = a
[num2ccode_thm] Theorem
|- (num2ccode 0 = Gt) ∧ (num2ccode 1 = Lt) ∧ (num2ccode 2 = Eq) ∧
(num2ccode 3 = Un)
[num2roundmode_11] Theorem
|- ∀r r'.
r < 4 ⇒
r' < 4 ⇒
((num2roundmode r = num2roundmode r') ⇔ (r = r'))
[num2roundmode_ONTO] Theorem
|- ∀a. ∃r. (a = num2roundmode r) ∧ r < 4
[num2roundmode_roundmode2num] Theorem
|- ∀a. num2roundmode (roundmode2num a) = a
[num2roundmode_thm] Theorem
|- (num2roundmode 0 = To_nearest) ∧
(num2roundmode 1 = float_To_zero) ∧
(num2roundmode 2 = To_pinfinity) ∧
(num2roundmode 3 = To_ninfinity)
[roundmode2num_11] Theorem
|- ∀a a'. (roundmode2num a = roundmode2num a') ⇔ (a = a')
[roundmode2num_ONTO] Theorem
|- ∀r. r < 4 ⇔ ∃a. r = roundmode2num a
[roundmode2num_num2roundmode] Theorem
|- ∀r. r < 4 ⇔ (roundmode2num (num2roundmode r) = r)
[roundmode2num_thm] Theorem
|- (roundmode2num To_nearest = 0) ∧
(roundmode2num float_To_zero = 1) ∧
(roundmode2num To_pinfinity = 2) ∧
(roundmode2num To_ninfinity = 3)
[roundmode_Axiom] Theorem
|- ∀x0 x1 x2 x3.
∃f.
(f To_nearest = x0) ∧ (f float_To_zero = x1) ∧
(f To_pinfinity = x2) ∧ (f To_ninfinity = x3)
[roundmode_EQ_roundmode] Theorem
|- ∀a a'. (a = a') ⇔ (roundmode2num a = roundmode2num a')
[roundmode_case_cong] Theorem
|- ∀M M' v0 v1 v2 v3.
(M = M') ∧ ((M' = To_nearest) ⇒ (v0 = v0')) ∧
((M' = float_To_zero) ⇒ (v1 = v1')) ∧
((M' = To_pinfinity) ⇒ (v2 = v2')) ∧
((M' = To_ninfinity) ⇒ (v3 = v3')) ⇒
((case M of
To_nearest => v0
| float_To_zero => v1
| To_pinfinity => v2
| To_ninfinity => v3) =
case M' of
To_nearest => v0'
| float_To_zero => v1'
| To_pinfinity => v2'
| To_ninfinity => v3')
[roundmode_case_def] Theorem
|- (∀v0 v1 v2 v3.
(case To_nearest of
To_nearest => v0
| float_To_zero => v1
| To_pinfinity => v2
| To_ninfinity => v3) =
v0) ∧
(∀v0 v1 v2 v3.
(case float_To_zero of
To_nearest => v0
| float_To_zero => v1
| To_pinfinity => v2
| To_ninfinity => v3) =
v1) ∧
(∀v0 v1 v2 v3.
(case To_pinfinity of
To_nearest => v0
| float_To_zero => v1
| To_pinfinity => v2
| To_ninfinity => v3) =
v2) ∧
∀v0 v1 v2 v3.
(case To_ninfinity of
To_nearest => v0
| float_To_zero => v1
| To_pinfinity => v2
| To_ninfinity => v3) =
v3
[roundmode_distinct] Theorem
|- To_nearest ≠ float_To_zero ∧ To_nearest ≠ To_pinfinity ∧
To_nearest ≠ To_ninfinity ∧ float_To_zero ≠ To_pinfinity ∧
float_To_zero ≠ To_ninfinity ∧ To_pinfinity ≠ To_ninfinity
[roundmode_induction] Theorem
|- ∀P.
P To_nearest ∧ P To_ninfinity ∧ P To_pinfinity ∧
P float_To_zero ⇒
∀a. P a
[roundmode_nchotomy] Theorem
|- ∀a.
(a = To_nearest) ∨ (a = float_To_zero) ∨ (a = To_pinfinity) ∨
(a = To_ninfinity)
*)
end
HOL 4, Kananaskis-10