src/Doc/ZF/FOL_examples.thy
 author wenzelm Sat, 05 Apr 2014 15:03:40 +0200 changeset 56421 1ffd7eaa778b parent 48985 5386df44a037 permissions -rw-r--r--
updated to jedit_build-20140405: Code2HTML.jar, CommonControls.jar, Console.jar, kappalayout.jar, Navigator.jar, SideKick.jar, doc with jEdit manuals (ant dist-manuals);
```
header{*Examples of Classical Reasoning*}

theory FOL_examples imports "~~/src/FOL/FOL" begin

lemma "EX y. ALL x. P(y)-->P(x)"
--{* @{subgoals[display,indent=0,margin=65]} *}
apply (rule exCI)
--{* @{subgoals[display,indent=0,margin=65]} *}
apply (rule allI)
--{* @{subgoals[display,indent=0,margin=65]} *}
apply (rule impI)
--{* @{subgoals[display,indent=0,margin=65]} *}
apply (erule allE)
--{* @{subgoals[display,indent=0,margin=65]} *}
txt{*see below for @{text allI} combined with @{text swap}*}
apply (erule allI [THEN [2] swap])
--{* @{subgoals[display,indent=0,margin=65]} *}
apply (rule impI)
--{* @{subgoals[display,indent=0,margin=65]} *}
apply (erule notE)
--{* @{subgoals[display,indent=0,margin=65]} *}
apply assumption
done

text {*
@{thm[display] allI [THEN [2] swap]}
*}

lemma "EX y. ALL x. P(y)-->P(x)"
by blast

end

```