Stream: Archive Mirror: Isabelle Users Mailing List

Topic: [isabelle] Can't isabelle-users@cl.cam.ac.uk


view this post on Zulip Email Gateway (Aug 17 2022 at 13:45):

From: Marc Weber <marco-oweber@gmx.de>
Hi I've tried to use ProofGeneral with this little example from the ETH
exercises:

--- simple.thy ----
theory simple=HOL:
lemma fist_theorem: "A-->(B-->A)"
apply(rule impl)
[... ^ error appears here ]
end


error:
** Error in method "FOL.rule":
*** Unknown theorem(s) "impl"
*** At command "apply".

Is this problem caused by isabelle or by my configuration of ProofGeneral?
I also can't use button [Command] of the ProofGeneral interface and
text "thm impl" to insert this command. (err: not found)

The first HOL example from the Isabell/Isar reference documentation
works.. (the whole buffer is marked blue at the end)

-- test.thy from Isabell/Isar documentation --
theory Foo imports Main begin;
constdefs foo:: nat "foo == 1"
lemma "0 < foo" by (simp add: foo_def);
end


Marc

view this post on Zulip Email Gateway (Aug 17 2022 at 13:45):

From: Makarius <makarius@sketis.net>
This looks like a problem with a sans serif font. The rule is called impI
-- with capitial i at the end -- for implication-introduction.

Makarius

view this post on Zulip Email Gateway (Aug 17 2022 at 13:45):

From: "Achim D. Brucker" <brucker@spamfence.net>
Hi,
Marc Weber <marco-oweber@gmx.de> schrieb:
the name of the rule is "impI" (the last letter is an
uppercase 'i') and not "impl". The name comes from
"implication _I_introduction.

Achim

view this post on Zulip Email Gateway (Aug 17 2022 at 13:45):

From: Mark A Hills <mhills@cs.uiuc.edu>
This is because impl is invalid -- you are intending to use impI
instead. So, this would work:

theory simple=HOL:
lemma first_theorem: "A-->(B-->A)"
apply(rule impI)
apply(rule impI)
apply assumption
done
end

Mark


Last updated: May 03 2024 at 08:18 UTC