I have modeled a system in ispin and when trying to verify the system using LTL formulas I found unreachable error like
unreached in claim l0
_spin_nvr.tmp:8, state 9, "(!((getReciept&&getCard)))"
_spin_nvr.tmp:10, state 11, "-end-"
(2 of 11 states)
my ltl formula was
ltl0{[]((cardeject && getCash) -> <>(getReciept && getCard))}