[isabelle-dev] NEWS: 'subgoal' command

[Lars Noschinski]

On 03.07.2015 04:02, Daniel Matichuk wrote:
> Additionally, fresh names are chosen for any free variables that appear in the subgoal
> 
> e.g.
> 
> lemma "⋀x y. A x y"
>   subgoal for A
> 
> Results in "x" being named "Aa". In this case I would expect either an error ("Free name clash") or for the new fixed term to shadow the free A.
> The second choice is a bit strange, however, because you end up with two different coloured "A"s in the goal.

I would expect unspecified variables to get internal names, i.e. names
ending with "_"; similar to variables not specified in a case command.