I was trying to go through the Isar chapter for Isabelle (theorem Prover) and the first statement has:
lemma "¬ surj(f :: 'a ⇒ 'a set)"
I wanted to understand what the constant surj
was. I know that it's easy to look up theorems with:
thm notI
which displays:
(?P ⟹ False) ⟹ ¬ ?P
I tried googling surj
but nothing useful came up.
I went to the documentation (https://isabelle.in.tum.de/documentation.html) but I couldn't find an easy way to search through it (e.g. with a search bar).
How do people search for definitions or general stuff when doing proofs? How do you look up things for Isabelle in an effective manner without having to resort to SO etc for trivial stuff (that I should probably be able to look up myself)? Like a man
command or a -help
flag etc?
I realized that there is a Query box at the bottom so I gave it a go. But it showed me 38 theorems. Thats good progress BUT I feel that because when I stated my lemma Isabelle knows exactly which one it is using. Is there a way to force Isabelle to reveal what definition it's using (since it obviously HAS to know what it's using).
I just noticed that:
thm surj_def
displays:
surj ?f = (∀y. ∃x. y = ?f x)
does display something...the question was worth it cuz I discovered the Query box but it would still be great how people develop in Isabelle regardless.
Edit:
it would also be nice if it linked to docs of tactics explaining what they did or something like that...
blast
(search.isabelle.in.tum.de/#search/…) but nothing came up. Is that a bug? What are the limits of your tool? – Addressee