Convert an Isar proof of forall-statement to apply

问题:

I'm trying to build a very short proof for a given fact. I would like to just use apply-style commands. Now my theorem's structure looks like this:

theorem 
  statement
  apply(some commands)
  proof -
    fix t assume "some predicate"
    from some assumptions "some_theorem"
    by(some commands)  
  qed

So, if I want to do my proof minimal, I should really attack the lines:

fix t assume "some predicate"
from some assumptions "some_theorem"

which is basically implementing the proof of a forall statement:

⋀ param. A ⟹ B

My question is is there a hack that will let me encode the proof of such an statement in apply-style instead of Isar proof language?