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.
Definition. We define SNoL_nonneg to be λx ⇒ {w ∈ SNoL x|0 w} of type setset.
Theorem. (SNoL_nonneg_0)
Proof:
Proof not loaded.
Theorem. (SNoL_nonneg_1)
Proof:
Proof not loaded.
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.
Theorem. (SNo_sqrtauxset_I)
∀Y Z x, ∀yY, ∀zZ, 0 < y + z(x + y * z) :/: (y + z) SNo_sqrtauxset Y Z x
Proof:
Proof not loaded.
Theorem. (SNo_sqrtauxset_E)
∀Y Z x, ∀uSNo_sqrtauxset Y Z x, ∀p : prop, (∀yY, ∀zZ, 0 < y + zu = (x + y * z) :/: (y + z)p)p
Proof:
Proof not loaded.
Theorem. (SNo_sqrtauxset_0)
∀Z x, SNo_sqrtauxset 0 Z x = 0
Proof:
Proof not loaded.
Theorem. (SNo_sqrtauxset_0')
∀Y x, SNo_sqrtauxset Y 0 x = 0
Proof:
Proof not loaded.
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.
Theorem. (SNo_sqrtaux_0)
∀x, ∀g : setset, SNo_sqrtaux x g 0 = ({g w|w ∈ SNoL_nonneg x},{g z|z ∈ SNoR x})
Proof:
Proof not loaded.
Theorem. (SNo_sqrtaux_S)
∀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)
Proof:
Proof not loaded.
Theorem. (SNo_sqrtaux_mon_lem)
∀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
Proof:
Proof not loaded.
Theorem. (SNo_sqrtaux_mon)
∀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
Proof:
Proof not loaded.
Theorem. (SNo_sqrtaux_ext)
∀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
Proof:
Proof not loaded.
Beginning of Section sqrt_SNo_nonneg
Let G : set(setset)setλx g ⇒ SNoCut (k ∈ ωSNo_sqrtaux x g k 0) (k ∈ ωSNo_sqrtaux x g k 1)
Definition. We define sqrt_SNo_nonneg to be SNo_rec_i G of type setset.
Theorem. (sqrt_SNo_nonneg_eq)
∀x, SNo xsqrt_SNo_nonneg x = G x sqrt_SNo_nonneg
Proof:
Proof not loaded.
Theorem. (sqrt_SNo_nonneg_prop1a)
∀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)
Proof:
Proof not loaded.
Theorem. (sqrt_SNo_nonneg_prop1b)
∀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)
Proof:
Proof not loaded.
Theorem. (sqrt_SNo_nonneg_prop1c)
∀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
Proof:
Proof not loaded.
Theorem. (sqrt_SNo_nonneg_prop1d)
∀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
Proof:
Proof not loaded.
Theorem. (sqrt_SNo_nonneg_prop1e)
∀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
Proof:
Proof not loaded.
Theorem. (sqrt_SNo_nonneg_prop1)
∀x, SNo x0 xSNo (sqrt_SNo_nonneg x)0 sqrt_SNo_nonneg xsqrt_SNo_nonneg x * sqrt_SNo_nonneg x = x
Proof:
Proof not loaded.
End of Section sqrt_SNo_nonneg
Theorem. (SNo_sqrtaux_0_1_prop)
∀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)
Proof:
Proof not loaded.
Theorem. (SNo_sqrtaux_0_prop)
∀x, SNo x0 x∀k, nat_p k∀ySNo_sqrtaux x sqrt_SNo_nonneg k 0, SNo y0 yy * y < x
Proof:
Proof not loaded.
Theorem. (SNo_sqrtaux_1_prop)
∀x, SNo x0 x∀k, nat_p k∀ySNo_sqrtaux x sqrt_SNo_nonneg k 1, SNo y0 yx < y * y
Proof:
Proof not loaded.
Theorem. (SNo_sqrt_SNo_SNoCutP)
∀x, SNo x0 xSNoCutP (k ∈ ωSNo_sqrtaux x sqrt_SNo_nonneg k 0) (k ∈ ωSNo_sqrtaux x sqrt_SNo_nonneg k 1)
Proof:
Proof not loaded.
Theorem. (SNo_sqrt_SNo_nonneg)
∀x, SNo x0 xSNo (sqrt_SNo_nonneg x)
Proof:
Proof not loaded.
Theorem. (sqrt_SNo_nonneg_nonneg)
∀x, SNo x0 x0 sqrt_SNo_nonneg x
Proof:
Proof not loaded.
Theorem. (sqrt_SNo_nonneg_sqr)
∀x, SNo x0 xsqrt_SNo_nonneg x * sqrt_SNo_nonneg x = x
Proof:
Proof not loaded.
Proof:
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Proof:
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End of Section SurrealSqrt