remove error "Duplicate session" cf. 07c2812b9ff3
actually this error is avoided by
~~$ ./bin/isabelle build -v -b Isac
instead of
~~$ ./bin/isabelle build -d src/Tools/isac/ -v -b Isac
1 (* Title: create a heap image for isac on Isabelle2013
2 Author: Walther Neuper, TU Graz, 130715
3 (c) due to copyright terms
5 $ cd /usr/local/isabisac/
6 $ ./bin/isabelle build -v -b Isac
9 ISABELLE_BROWSER_INFO="$ISABELLE_HOME_USER/browser_info"
10 before out-outcommenting (*, browser_info = true*) below and ...
11 $ ./bin/isabelle build -o browser_info -v -c HOL
12 $ ./bin/isabelle build -o browser_info -d src/Tools/isac/ -v -b Isac
15 session Isac in "~~/src/Tools/isac" = HOL +
17 Isac core, prototype of a math-engine and knowledge
18 for a TP-based educational mathematics assistant.
20 The java front-end is under development at TU Graz,
21 the PolyML math-engine and Isabelle knowledge at RISC Linz.
22 See http://www.ist.tugraz.at/isac/.
24 options [document = false (*, browser_info = true*)]