src/HOL/Hyperreal/Ln.thy
changeset 22654 c2b6b5a9e136
parent 20692 6df83a636e67
child 22998 97e1f9c2cc46
equal deleted inserted replaced
22653:8e016bfdbf2f 22654:c2b6b5a9e136
   307   apply (subst exp_le_cancel_iff)
   307   apply (subst exp_le_cancel_iff)
   308   apply (subgoal_tac "ln (1 - (- x)) <= - (- x)")
   308   apply (subgoal_tac "ln (1 - (- x)) <= - (- x)")
   309   apply simp
   309   apply simp
   310   apply (rule ln_one_minus_pos_upper_bound) 
   310   apply (rule ln_one_minus_pos_upper_bound) 
   311   apply auto
   311   apply auto
   312   apply (rule sym) 
       
   313   apply (subst exp_ln_iff)
       
   314   apply auto
       
   315 done
   312 done
   316 
   313 
   317 lemma ln_add_one_self_le_self2: "-1 < x ==> ln(1 + x) <= x"
   314 lemma ln_add_one_self_le_self2: "-1 < x ==> ln(1 + x) <= x"
   318   apply (subgoal_tac "x = ln (exp x)")
   315   apply (subgoal_tac "x = ln (exp x)")
   319   apply (erule ssubst)back
   316   apply (erule ssubst)back