FAQs for using Proof General ============================ With thanks to the anonymous authors of questions/answers below. For latest version, see http://proofgeneral.inf.ed.ac.uk/FAQ Please also check the BUGS file. ----------------------------------------------------------------- Q. Emacs appears to hang when the prover process is started. A. This may be because of UTF-8 issues e.g in Red Hat 8.0/9/glibc 2.2 RedHat 8 and later has glibc 2.2 and UTF8 encoded output may be turned on in default locale. Unfortunately Proof General relies on 8-bit characters which are UTF8 prefixes in the output of proof assistants (inc Coq, Isabelle). These prefix characters are not flushed to stdout individually. As a workaround we must find a way to disable interpretation of UTF8 in the C libraries that Coq and friends use. Doing this inside PG/Emacs seems tricky; locale settings are set/inherited in strange ways. One solution is to run the Emacs process itself in a different locale, for example, starting XEmacs by typing: $ LANG=en_GB xemacs & Another solution is to set LANG inside a file ~/.i18n, which will be read the shell. This will affect all applications, though. [ suggestions for a better workaround inside Emacs would be welcome ] ----------------------------------------------------------------- Q. XEmacs appears to hang on certain malformed inputs to the prover. A. This symptom may be caused by using non-Mule versions of XEmacs. Please make sure you use a Mule-enabled version. ----------------------------------------------------------------- Q. XEmacs 21.4 displays a progress bar during fontification which sometimes gets stuck or messes up the display. Is this a Proof General bug? What can I do? A. This is an XEmacs bug. What you can do is prevent the use of the ugly widget, for example by adding (setq progress-feedback-use-echo-area t) inside your configuration file `.xemacs/init.el'. ----------------------------------------------------------------- Q. I have a problem installing/using Proof General, what can I do? A. Please check the documentation carefully, particularly the requirements for a full-featured and recent Emacs version, as mentioned in INSTALL (see "Dependency on Other Emacs Packages"). If you still cannot solve your problem, send a message to da+pg-support@inf.ed.ac.uk in the first instance. ----------------------------------------------------------------- Q. I'm using Proof General for prover X, then I load a file for prover Y. The buffer doesn't enter the mode for prover Y. Why not? A. Unfortunately the architecture of Proof General is designed so that you can only use one prover at a time in the same Emacs session. If you want to run more than one prover at a time, you have to run more than one Emacs. ----------------------------------------------------------------- Q. I have just installed Emacs, ProofGeneral and a proof assistant. It works but X-Symbol is not being activated. A. Once X-Symbol is picked up by Emacs (e.g. is working for TeX), you should enable it inside Proof General by the menu item: Proof-General -> Options -> X-Symbol To enable it automatically every time you use Proof General, type M-x customize-variable RET isar-x-symbol-enable RET and change/set/save the setting to `on'. Note that we don't do this by default, because from the system's perspective it is difficult to determine if this will succeed --- or just produce funny characters that confuse new users even more. If you are using Isabelle, the wrapper script will load X-Symbol from any location, and you can enable it by passing the option "-x true". ----------------------------------------------------------------- Q. I notice that editing Isabelle files in Proof General with XEmacs 21.4 is very slow. Can this be fixed? A. You could consider adding the following line to your init file: (setq lookup-syntax-properties nil) This hack bypasses some very slow code in the font-lock system, but it also disables some syntax-related features, so use with care. ----------------------------------------------------------------- Q. I'm afraid I got stuck very early on. I sent the following line: by (swap_res_tac [psubsetI] 1; Notice that I forgot the right bracket. The line went pink, the buffer went read-only and nothing I tried would let me fix the error. A. The proof process is waiting for more input, but Proof General doesn't realise this and waits for a response. You should type something in the proof shell, or interrupt the process with C-c C-c or the Stop button. ----------------------------------------------------------------- Q. How can I keep the Proof General option settings across sessions? A. For options set in the Proof General -> Options menu use the "Save Options" menu item (Proof General -> Options -> Save Options). For other options set via customize (Proof General -> Advanced -> Customize), use the customize buttons, or M-x customize-save-customized. ----------------------------------------------------------------- Q. How do I use Proof General for Isabelle classic instead of Isabelle/Isar? A. There are several ways: 1. Use the Isabelle settings mechanism, invoke with "Isabelle" 2. Set the environment variable PROOFGENERAL_ASSISTANTS=isa before starting Emacs. 3. Put the line (* -*- isa -*- *) at the top of your files. Unfortunately Isabelle/Isar and Isabelle classic are two quite separate Proof General instances. Ideally they should be combined into one, if anyone fancies some elisp hacking... ----------------------------------------------------------------- Q. When using X-Symbol, why do I sometimes see funny characters like \233 in the buffer? A. These are part of the 8 bit character codes used by X Symbol to get symbols from particular fonts. Sometimes X-Symbol forgets to fontify the buffer properly to make it use the right fonts. (That's being rather unkind to X-Symbol: several things can go wrong one way or another). To fix, type M-x x-symbol-decode-recorde If that doesn't work, type M-x font-lock-mode twice to turn font-lock off then on. Or reload the file. Note that X-Symbol is more robust when used with XEmacs/Mule. Read the X-Symbol documentation for (much) more information. http://x-symbol.sourceforge.net/man/ ----------------------------------------------------------------- Q. I would like to use the X-Symbol fonts in PG not just at the standard size but also for larger sizes since I use PG during talks, where I set the font size to 24. A. Nobody has designed large versions of the X-Symbol fonts but it is possible to scale-up the existing ones, by adding (setq x-symbol-xsymb1-fonts '(("-xsymb-xsymb1-medium-r-normal-*-*-240-*-*-*-*-xsymb-xsymb1") ("-xsymb-xsymb1_sub-medium-r-normal-*-*-180-*-*-*-*-xsymb-xsymb1") ("-xsymb-xsymb1_sup-medium-r-normal-*-*-180-*-*-*-*-xsymb-xsymb1"))) (setq x-symbol-xsymb0-fonts '(("-adobe-symbol-medium-r-normal-*-*-240-*-*-*-*-adobe-fontspecific" "-xsymb-xsymb0-medium-r-normal--*-240-75-75-p-85-adobe-fontspecific") ("-xsymb-xsymb0_sub-medium-r-normal--18-180-75-75-p-74-adobe-fontspecific" "-adobe-symbol_sub-medium-r-normal-*-*-180-*-*-*-*-adobe-fontspecific") ("-xsymb-xsymb0_sup-medium-r-normal--18-180-75-75-p-74-adobe-fontspecific" "-adobe-symbol_sup-medium-r-normal-*-*-180-*-*-*-*-adobe-fontspecific"))) to your .emacs, which causes the special fonts to come up in size 24; the normal font you can change manually. Of course you can also select smaller sizes. Most of the symbols look reasonable, except that they appear almost bold. For more information about this, see the X-Symbol FAQ, at http://x-symbol.sourceforge.net/man/x-symbol_8.html#SEC100 ----------------------------------------------------------------- Q. Can I join any mailing lists for Proof General? A. Of course, email "proofgeneral-request@informatics.ed.ac.uk" with the line "subscribe" in the message body, to join the user's and announcements list. There is also a list for developers, proofgeneral-devel Visit http://www.proofgeneral.org/mailinglist for more details. ----------------------------------------------------------------- Q. I see spurious ^M characters at the end of lines in the windows showing output from the prover. How can I remove them? A. Customize the value of `proof-shell-strip-crs-from-output'. ----------------------------------------------------------------- $Id$