etc/user-settings.sample

added parallel_proofs flag (default true, cf. usedir option -Q), which can be disabled in low-memory situations;

# -*- shell-script -*-
#
# Isabelle user settings sample -- for use in ~/.isabelle/etc/settings

ISABELLE_USEDIR_OPTIONS="-i true -d pdf"
HOL_USEDIR_OPTIONS="-p 1"
ISABELLE_LOGIC=HOL