src/HOL/Deriv.thy
changeset 62390 842917225d56
parent 61976 3a27957ac658
child 62398 a4b68bf18f8d
equal deleted inserted replaced
62380:29800666e526 62390:842917225d56
   960   proof (intro exI conjI strip)
   960   proof (intro exI conjI strip)
   961     show "0<s" using s .
   961     show "0<s" using s .
   962     fix h::real
   962     fix h::real
   963     assume "0 < h" "h < s"
   963     assume "0 < h" "h < s"
   964     with all [of h] show "f x < f (x+h)"
   964     with all [of h] show "f x < f (x+h)"
   965     proof (simp add: abs_if pos_less_divide_eq split add: split_if_asm)
   965     proof (simp add: abs_if pos_less_divide_eq split add: if_split_asm)
   966       assume "~ (f (x+h) - f x) / h < l" and h: "0 < h"
   966       assume "~ (f (x+h) - f x) / h < l" and h: "0 < h"
   967       with l
   967       with l
   968       have "0 < (f (x+h) - f x) / h" by arith
   968       have "0 < (f (x+h) - f x) / h" by arith
   969       thus "f x < f (x+h)"
   969       thus "f x < f (x+h)"
   970   by (simp add: pos_less_divide_eq h)
   970   by (simp add: pos_less_divide_eq h)
   989   proof (intro exI conjI strip)
   989   proof (intro exI conjI strip)
   990     show "0<s" using s .
   990     show "0<s" using s .
   991     fix h::real
   991     fix h::real
   992     assume "0 < h" "h < s"
   992     assume "0 < h" "h < s"
   993     with all [of "-h"] show "f x < f (x-h)"
   993     with all [of "-h"] show "f x < f (x-h)"
   994     proof (simp add: abs_if pos_less_divide_eq split add: split_if_asm)
   994     proof (simp add: abs_if pos_less_divide_eq split add: if_split_asm)
   995       assume " - ((f (x-h) - f x) / h) < l" and h: "0 < h"
   995       assume " - ((f (x-h) - f x) / h) < l" and h: "0 < h"
   996       with l
   996       with l
   997       have "0 < (f (x-h) - f x) / h" by arith
   997       have "0 < (f (x-h) - f x) / h" by arith
   998       thus "f x < f (x-h)"
   998       thus "f x < f (x-h)"
   999   by (simp add: pos_less_divide_eq h)
   999   by (simp add: pos_less_divide_eq h)