Beginning of Section SurrealSqrt
Notation. We use - as a prefix operator with priority 358 corresponding to applying term minus_SNo.
Notation. We use + as an infix operator with priority 360 and which associates to the right corresponding to applying term add_SNo.
Notation. We use * as an infix operator with priority 355 and which associates to the right corresponding to applying term mul_SNo.
Notation. We use :/: as an infix operator with priority 353 and no associativity corresponding to applying term div_SNo.
Notation. We use < as an infix operator with priority 490 and no associativity corresponding to applying term SNoLt.
Notation. We use as an infix operator with priority 490 and no associativity corresponding to applying term SNoLe.
Notation. We use ^ as an infix operator with priority 342 and which associates to the right corresponding to applying term exp_SNo_nat.
L18
Definition. We define SNoL_nonneg to be λx ⇒ {w ∈ SNoL x|0 w} of type setset.
L19
Axiom. (SNoL_nonneg_0) We take the following as an axiom:
L20
Axiom. (SNoL_nonneg_1) We take the following as an axiom:
L21
Definition. We define SNo_sqrtauxset to be λY Z x ⇒ y ∈ Y{(x + y * z) :/: (y + z)|z ∈ Z, 0 < y + z} of type setsetsetset.
L22
Axiom. (SNo_sqrtauxset_I) We take the following as an axiom:
∀Y Z x, ∀yY, ∀zZ, 0 < y + z(x + y * z) :/: (y + z) SNo_sqrtauxset Y Z x
L23
Axiom. (SNo_sqrtauxset_E) We take the following as an axiom:
∀Y Z x, ∀uSNo_sqrtauxset Y Z x, ∀p : prop, (∀yY, ∀zZ, 0 < y + zu = (x + y * z) :/: (y + z)p)p
L24
Axiom. (SNo_sqrtauxset_0) We take the following as an axiom:
∀Z x, SNo_sqrtauxset 0 Z x = 0
L25
Axiom. (SNo_sqrtauxset_0') We take the following as an axiom:
∀Y x, SNo_sqrtauxset Y 0 x = 0
L26
Definition. We define SNo_sqrtaux to be λx g ⇒ nat_primrec ({g w|w ∈ SNoL_nonneg x},{g z|z ∈ SNoR x}) (λk p ⇒ (p 0SNo_sqrtauxset (p 0) (p 1) x,p 1SNo_sqrtauxset (p 0) (p 0) xSNo_sqrtauxset (p 1) (p 1) x)) of type set(setset)setset.
L27
Axiom. (SNo_sqrtaux_0) We take the following as an axiom:
∀x, ∀g : setset, SNo_sqrtaux x g 0 = ({g w|w ∈ SNoL_nonneg x},{g z|z ∈ SNoR x})
L28
Axiom. (SNo_sqrtaux_S) We take the following as an axiom:
∀x, ∀g : setset, ∀n, nat_p nSNo_sqrtaux x g (ordsucc n) = (SNo_sqrtaux x g n 0SNo_sqrtauxset (SNo_sqrtaux x g n 0) (SNo_sqrtaux x g n 1) x,SNo_sqrtaux x g n 1SNo_sqrtauxset (SNo_sqrtaux x g n 0) (SNo_sqrtaux x g n 0) xSNo_sqrtauxset (SNo_sqrtaux x g n 1) (SNo_sqrtaux x g n 1) x)
L29
Axiom. (SNo_sqrtaux_mon_lem) We take the following as an axiom:
∀x, ∀g : setset, ∀m, nat_p m∀n, nat_p nSNo_sqrtaux x g m 0 SNo_sqrtaux x g (add_nat m n) 0SNo_sqrtaux x g m 1 SNo_sqrtaux x g (add_nat m n) 1
L30
Axiom. (SNo_sqrtaux_mon) We take the following as an axiom:
∀x, ∀g : setset, ∀m, nat_p m∀n, nat_p nm nSNo_sqrtaux x g m 0 SNo_sqrtaux x g n 0SNo_sqrtaux x g m 1 SNo_sqrtaux x g n 1
L31
Axiom. (SNo_sqrtaux_ext) We take the following as an axiom:
∀x, SNo x∀g h : setset, (∀x'SNoS_ (SNoLev x), g x' = h x')∀k, nat_p kSNo_sqrtaux x g k = SNo_sqrtaux x h k
Beginning of Section sqrt_SNo_nonneg
L33
Let G : set(setset)setλx g ⇒ SNoCut (k ∈ ωSNo_sqrtaux x g k 0) (k ∈ ωSNo_sqrtaux x g k 1)
L35
Definition. We define sqrt_SNo_nonneg to be SNo_rec_i G of type setset.
L36
Axiom. (sqrt_SNo_nonneg_eq) We take the following as an axiom:
∀x, SNo xsqrt_SNo_nonneg x = G x sqrt_SNo_nonneg
L37
Axiom. (sqrt_SNo_nonneg_prop1a) We take the following as an axiom:
∀x, SNo x0 x(∀wSNoS_ (SNoLev x), 0 wSNo (sqrt_SNo_nonneg w)0 sqrt_SNo_nonneg wsqrt_SNo_nonneg w * sqrt_SNo_nonneg w = w)∀k, nat_p k(∀ySNo_sqrtaux x sqrt_SNo_nonneg k 0, SNo y0 yy * y < x)(∀ySNo_sqrtaux x sqrt_SNo_nonneg k 1, SNo y0 yx < y * y)
L38
Axiom. (sqrt_SNo_nonneg_prop1b) We take the following as an axiom:
∀x, SNo x0 x(∀k, nat_p k(∀ySNo_sqrtaux x sqrt_SNo_nonneg k 0, SNo y0 yy * y < x)(∀ySNo_sqrtaux x sqrt_SNo_nonneg k 1, SNo y0 yx < y * y))SNoCutP (k ∈ ωSNo_sqrtaux x sqrt_SNo_nonneg k 0) (k ∈ ωSNo_sqrtaux x sqrt_SNo_nonneg k 1)
L39
Axiom. (sqrt_SNo_nonneg_prop1c) We take the following as an axiom:
∀x, SNo x0 xSNoCutP (k ∈ ωSNo_sqrtaux x sqrt_SNo_nonneg k 0) (k ∈ ωSNo_sqrtaux x sqrt_SNo_nonneg k 1)(∀z(k ∈ ωSNo_sqrtaux x sqrt_SNo_nonneg k 1), ∀p : prop, (SNo z0 zx < z * zp)p)0 G x sqrt_SNo_nonneg
L40
Axiom. (sqrt_SNo_nonneg_prop1d) We take the following as an axiom:
∀x, SNo x0 x(∀wSNoS_ (SNoLev x), 0 wSNo (sqrt_SNo_nonneg w)0 sqrt_SNo_nonneg wsqrt_SNo_nonneg w * sqrt_SNo_nonneg w = w)SNoCutP (k ∈ ωSNo_sqrtaux x sqrt_SNo_nonneg k 0) (k ∈ ωSNo_sqrtaux x sqrt_SNo_nonneg k 1)0 G x sqrt_SNo_nonnegG x sqrt_SNo_nonneg * G x sqrt_SNo_nonneg < xFalse
L41
Axiom. (sqrt_SNo_nonneg_prop1e) We take the following as an axiom:
∀x, SNo x0 x(∀wSNoS_ (SNoLev x), 0 wSNo (sqrt_SNo_nonneg w)0 sqrt_SNo_nonneg wsqrt_SNo_nonneg w * sqrt_SNo_nonneg w = w)SNoCutP (k ∈ ωSNo_sqrtaux x sqrt_SNo_nonneg k 0) (k ∈ ωSNo_sqrtaux x sqrt_SNo_nonneg k 1)0 G x sqrt_SNo_nonnegx < G x sqrt_SNo_nonneg * G x sqrt_SNo_nonnegFalse
L42
Axiom. (sqrt_SNo_nonneg_prop1) We take the following as an axiom:
∀x, SNo x0 xSNo (sqrt_SNo_nonneg x)0 sqrt_SNo_nonneg xsqrt_SNo_nonneg x * sqrt_SNo_nonneg x = x
End of Section sqrt_SNo_nonneg
L44
Axiom. (SNo_sqrtaux_0_1_prop) We take the following as an axiom:
∀x, SNo x0 x∀k, nat_p k(∀ySNo_sqrtaux x sqrt_SNo_nonneg k 0, SNo y0 yy * y < x)(∀ySNo_sqrtaux x sqrt_SNo_nonneg k 1, SNo y0 yx < y * y)
L45
Axiom. (SNo_sqrtaux_0_prop) We take the following as an axiom:
∀x, SNo x0 x∀k, nat_p k∀ySNo_sqrtaux x sqrt_SNo_nonneg k 0, SNo y0 yy * y < x
L46
Axiom. (SNo_sqrtaux_1_prop) We take the following as an axiom:
∀x, SNo x0 x∀k, nat_p k∀ySNo_sqrtaux x sqrt_SNo_nonneg k 1, SNo y0 yx < y * y
L47
Axiom. (SNo_sqrt_SNo_SNoCutP) We take the following as an axiom:
∀x, SNo x0 xSNoCutP (k ∈ ωSNo_sqrtaux x sqrt_SNo_nonneg k 0) (k ∈ ωSNo_sqrtaux x sqrt_SNo_nonneg k 1)
L48
Axiom. (SNo_sqrt_SNo_nonneg) We take the following as an axiom:
∀x, SNo x0 xSNo (sqrt_SNo_nonneg x)
L49
Axiom. (sqrt_SNo_nonneg_nonneg) We take the following as an axiom:
∀x, SNo x0 x0 sqrt_SNo_nonneg x
L50
Axiom. (sqrt_SNo_nonneg_sqr) We take the following as an axiom:
∀x, SNo x0 xsqrt_SNo_nonneg x * sqrt_SNo_nonneg x = x
L51
Axiom. (sqrt_SNo_nonneg_0) We take the following as an axiom:
L52
Axiom. (sqrt_SNo_nonneg_1) We take the following as an axiom:
End of Section SurrealSqrt