Structure intExtensionTheory

signature intExtensionTheory =
sig
  type thm = Thm.thm

  (*  Definitions  *)
    val SGN_def : thm

  (*  Theorems  *)
    val INT_ABS_CALCULATE_0 : thm
    val INT_ABS_CALCULATE_NEG : thm
    val INT_ABS_CALCULATE_POS : thm
    val INT_ABS_NOT0POS : thm
    val INT_EQ_RMUL_EXP : thm
    val INT_GT0_IMP_NOT0 : thm
    val INT_GT_RMUL_EXP : thm
    val INT_LT_ADD_NEG : thm
    val INT_LT_RMUL_EXP : thm
    val INT_MUL_POS_SIGN : thm
    val INT_NE_IMP_LTGT : thm
    val INT_NOT0_MUL : thm
    val INT_NOT0_SGNNOT0 : thm
    val INT_NOTGT_IMP_EQLT : thm
    val INT_NOTLTEQ_GT : thm
    val INT_NOTPOS0_NEG : thm
    val INT_NO_ZERODIV : thm
    val INT_SGN_CASES : thm
    val INT_SGN_CLAUSES : thm
    val INT_SGN_MUL : thm
    val INT_SGN_MUL2 : thm
    val INT_SGN_NOTPOSNEG : thm
    val INT_SGN_TOTAL : thm
    val LESS_IMP_NOT_0 : thm

  val intExtension_grammars : type_grammar.grammar * term_grammar.grammar
(*
   [Omega] Parent theory of "intExtension"

   [int_arith] Parent theory of "intExtension"

   [integerRing] Parent theory of "intExtension"

   [numRing] Parent theory of "intExtension"

   [SGN_def]  Definition

      |- ∀x. SGN x = if x = 0 then 0 else if x < 0 then -1 else 1

   [INT_ABS_CALCULATE_0]  Theorem

      |- ABS 0 = 0

   [INT_ABS_CALCULATE_NEG]  Theorem

      |- ∀a. a < 0 ⇒ (ABS a = -a)

   [INT_ABS_CALCULATE_POS]  Theorem

      |- ∀a. 0 < a ⇒ (ABS a = a)

   [INT_ABS_NOT0POS]  Theorem

      |- ∀x. x ≠ 0 ⇒ 0 < ABS x

   [INT_EQ_RMUL_EXP]  Theorem

      |- ∀a b n. 0 < n ⇒ ((a = b) ⇔ (a * n = b * n))

   [INT_GT0_IMP_NOT0]  Theorem

      |- ∀a. 0 < a ⇒ a ≠ 0

   [INT_GT_RMUL_EXP]  Theorem

      |- ∀a b n. 0 < n ⇒ (a > b ⇔ a * n > b * n)

   [INT_LT_ADD_NEG]  Theorem

      |- ∀x y. x < 0 ∧ y < 0 ⇒ x + y < 0

   [INT_LT_RMUL_EXP]  Theorem

      |- ∀a b n. 0 < n ⇒ (a < b ⇔ a * n < b * n)

   [INT_MUL_POS_SIGN]  Theorem

      |- ∀a b. 0 < a ⇒ 0 < b ⇒ 0 < a * b

   [INT_NE_IMP_LTGT]  Theorem

      |- ∀x. x ≠ 0 ⇔ 0 < x ∨ x < 0

   [INT_NOT0_MUL]  Theorem

      |- ∀a b. a ≠ 0 ⇒ b ≠ 0 ⇒ a * b ≠ 0

   [INT_NOT0_SGNNOT0]  Theorem

      |- ∀x. x ≠ 0 ⇒ SGN x ≠ 0

   [INT_NOTGT_IMP_EQLT]  Theorem

      |- ∀n. ¬(n < 0) ⇔ (0 = n) ∨ 0 < n

   [INT_NOTLTEQ_GT]  Theorem

      |- ∀a. ¬(a < 0) ⇒ a ≠ 0 ⇒ 0 < a

   [INT_NOTPOS0_NEG]  Theorem

      |- ∀a. ¬(0 < a) ⇒ a ≠ 0 ⇒ 0 < -a

   [INT_NO_ZERODIV]  Theorem

      |- ∀x y. (x = 0) ∨ (y = 0) ⇔ (x * y = 0)

   [INT_SGN_CASES]  Theorem

      |- ∀a P.
           ((SGN a = -1) ⇒ P) ∧ ((SGN a = 0) ⇒ P) ∧ ((SGN a = 1) ⇒ P) ⇒ P

   [INT_SGN_CLAUSES]  Theorem

      |- ∀x.
           ((SGN x = -1) ⇔ x < 0) ∧ ((SGN x = 0) ⇔ (x = 0)) ∧
           ((SGN x = 1) ⇔ x > 0)

   [INT_SGN_MUL]  Theorem

      |- ∀x1 x2 y1 y2.
           (SGN x1 = y1) ⇒ (SGN x2 = y2) ⇒ (SGN (x1 * x2) = y1 * y2)

   [INT_SGN_MUL2]  Theorem

      |- ∀x y. SGN (x * y) = SGN x * SGN y

   [INT_SGN_NOTPOSNEG]  Theorem

      |- ∀x. SGN x ≠ -1 ⇒ SGN x ≠ 1 ⇒ (SGN x = 0)

   [INT_SGN_TOTAL]  Theorem

      |- ∀a. (SGN a = -1) ∨ (SGN a = 0) ∨ (SGN a = 1)

   [LESS_IMP_NOT_0]  Theorem

      |- ∀n. 0 < n ⇒ n ≠ 0


*)
end

HOL 4, Kananaskis-10