def apply_fst_rule(net):
"""
Apply the Fusion of Series Transitions (FST) rule
Parameters
--------------
net
Reset Inhibitor net
"""
cont = True
while cont:
cont = False
for p, t, u in itertools.product(net.places, net.transitions, net.transitions):
if (len(list(p.in_arcs)) == 1 and list(p.in_arcs)[0].source == t) and \
(len(list(p.out_arcs)) == 1 and list(p.out_arcs)[0].target == u) and \
(len(list(u.in_arcs)) == 1 and list(u.in_arcs)[0].source == p) and \
(len(post_set(t).intersection(post_set(u))) == 0) and \
(set().union(*[post_set(place, properties.INHIBITOR_ARC) for place in post_set(u)]) == post_set(p,
properties.INHIBITOR_ARC)) and \
(set().union(*[post_set(place, properties.RESET_ARC) for place in post_set(u)]) == post_set(p,
properties.RESET_ARC)) and \
(len(pre_set(u, properties.RESET_ARC)) == 0 and len(pre_set(u, properties.INHIBITOR_ARC)) == 0):
if u.label == None:
remove_place(net, p)
for target in post_set(u):
add_arc_from_to(t, target, net)
remove_transition(net, u)
cont = True
break
return net
def loop_requirement(t1, t2):
if t1 == t2:
return False
for p in pn_util.pre_set(t2):
if len(pn_util.pre_set(p)
) != 1: # check that the preset of the t2 preset has one entry
return False
if t1 not in pn_util.pre_set(
p): # check that t1 is the unique way to mark the preset of t2
return False
for p in pn_util.post_set(t2):
if len(pn_util.post_set(p)) != 1:
return False
if t1 not in pn_util.post_set(p):
return False
for p in pn_util.pre_set(t1):
if len(pn_util.post_set(p)) != 1:
return False
if t1 not in pn_util.post_set(p):
return False
if t2 not in pn_util.pre_set(p): # t2 has to enable t1!
return False
for p in pn_util.post_set(t1):
if len(pn_util.pre_set(p)
) != 1: # check that the preset of the t2 preset has one entry
return False
if t1 not in pn_util.pre_set(
p): # check that t1 is the unique way to mark the preset of t2
return False
if t2 not in pn_util.post_set(p):
return False
return True
def apply_fpp_rule(net, im=None):
"""
Apply the Fusion of Parallel Places (FPP) rule
Parameters
--------------
net
Reset Inhibitor net
"""
if im is None:
im = {}
cont = True
while cont:
cont = False
for Q in power_set(net.places, 2):
condition = True
for x, y in itertools.product(Q, Q):
if x != y:
if not ((pre_set(x) == pre_set(y)) and \
(post_set(x) == post_set(y)) and \
(post_set(x, properties.RESET_ARC) == post_set(y, properties.RESET_ARC)) and \
(post_set(x, properties.INHIBITOR_ARC) == post_set(y, properties.INHIBITOR_ARC))):
condition = False
break
for x in Q:
if x in im:
for y in Q:
if y in im and im[x] > im[y]:
if not (len(post_set(x, properties.INHIBITOR_ARC)) == 0):
condition = False
break
else:
continue
break
# Q is a valid candidate
if condition:
# remove places except the first one
for p in Q[1:]:
remove_place(net, p)
cont = True
break
return net
def apply_a_rule(net):
"""
Apply the Abstraction (A) rule
Parameters
--------------
net
Reset Inhibitor net
"""
cont = True
while cont:
cont = False
for Q, U in itertools.product(power_set(net.places, 1), power_set(net.transitions, 1)):
for s, t in itertools.product([s for s in net.places if s not in Q],
[t for t in net.transitions if (t not in U) and (t.label == None)]):
if ((pre_set(t) == {s}) and \
(post_set(s) == {t}) and \
(pre_set(s) == set(U)) and \
(post_set(t) == set(Q)) and \
(len(set(itertools.product(pre_set(s), post_set(t))).intersection(
set([(arc.source, arc.target) for arc in net.arcs if
get_arc_type(arc) is None])))) == 0) and \
(len(pre_set(t, properties.RESET_ARC)) == 0) and \
(len(pre_set(t, properties.INHIBITOR_ARC)) == 0):
# check conditions on Q
condition = True
for q in Q:
if not ((post_set(s, properties.RESET_ARC) == post_set(q, properties.RESET_ARC)) and \
(post_set(s, properties.INHIBITOR_ARC) == post_set(q, properties.INHIBITOR_ARC))):
condition = False
break
# Q is a valid candidate
if condition:
for u in U:
for q in Q:
add_arc_from_to(u, q, net)
remove_place(net, s)
remove_transition(net, t)
cont = True
break
return net
def apply_r_rule(net):
"""
Apply the Reset Reduction (R) rule
Parameters
--------------
net
Reset Inhibitor net
"""
cont = True
while cont:
cont = False
for p, t in itertools.product(net.places, net.transitions):
if p in pre_set(t, properties.RESET_ARC).intersection(pre_set(t, properties.INHIBITOR_ARC)):
for arc in [arc for arc in net.arcs]:
if arc.source == p and arc.target == t and arc.arc_type == properties.RESET_ARC:
remove_arc(net, arc)
cont = True
break
return net
def apply_fpt_rule(net):
"""
Apply the Fusion of Parallel Transitions (FPT) rule
Parameters
--------------
net
Reset Inhibitor net
"""
cont = True
while cont:
cont = False
for V in power_set([transition for transition in net.transitions if transition.label == None], 2):
condition = True
for x, y in itertools.product(V, V):
if x != y:
if not ((pre_set(x) == pre_set(y)) and \
(post_set(x) == post_set(y)) and \
(pre_set(x, properties.RESET_ARC) == pre_set(y, properties.RESET_ARC)) and \
(pre_set(x, properties.INHIBITOR_ARC) == pre_set(y, properties.INHIBITOR_ARC))):
condition = False
break
# V is a valid candidate
if condition:
# remove transitions except the first one
for t in V[1:]:
remove_transition(net, t)
cont = True
break
return net
def apply_elt_rule(net):
"""
Apply the Elimination of Self-Loop Transitions (ELT) rule
Parameters
--------------
net
Reset Inhibitor net
"""
cont = True
while cont:
cont = False
for p, t in itertools.product(net.places, [t for t in net.transitions if t.label == None]):
if (len(list(t.in_arcs)) == 1 and list(t.in_arcs)[0].source == p) and \
(len(list(t.out_arcs)) == 1 and list(t.out_arcs)[0].target == p) and \
(len(list(p.in_arcs)) >= 2) and \
(len(pre_set(t, properties.RESET_ARC)) == 0 and len(pre_set(t, properties.INHIBITOR_ARC)) == 0):
remove_transition(net, t)
cont = True
break
return net
def apply_fsp_rule(net, im=None, fm=None):
"""
Apply the Fusion of Series Places (FSP) rule
Parameters
--------------
net
Reset Inhibitor net
"""
if im is None:
im = {}
if fm is None:
fm = {}
cont = True
while cont:
cont = False
for p, q, t in itertools.product(net.places, net.places, net.transitions):
if t.label == None: # only silent transitions may be removed either way
if (len(t.in_arcs) == 1 and list(t.in_arcs)[0].source == p) and \
(len(t.out_arcs) == 1 and list(t.out_arcs)[0].target == q) and \
(len(post_set(p)) == 1 and list(post_set(p))[0] == t) and \
(len(pre_set(p).intersection(pre_set(q))) == 0) and \
(post_set(p, properties.RESET_ARC) == post_set(q, properties.RESET_ARC)) and \
(post_set(p, properties.INHIBITOR_ARC) == post_set(q, properties.INHIBITOR_ARC)) and \
(len(pre_set(t, properties.RESET_ARC)) == 0 and len(
pre_set(t, properties.INHIBITOR_ARC)) == 0):
# remove place p and transition t
remove_transition(net, t)
for source in pre_set(p):
add_arc_from_to(source, q, net)
remove_place(net, p)
if p in im:
del im[p]
im[q] = 1
cont = True
break
return net, im, fm
def sequence_requirement(t1, t2):
if t1 == t2:
return False
if len(pn_util.pre_set(t2)) == 0:
return False
for p in pn_util.post_set(t1):
if len(pn_util.pre_set(p)) != 1 or len(pn_util.post_set(p)) != 1:
return False
if t1 not in pn_util.pre_set(p):
return False
if t2 not in pn_util.post_set(p):
return False
for p in pn_util.pre_set(t2):
if len(pn_util.pre_set(p)) != 1 or len(pn_util.post_set(p)) != 1:
return False
if t1 not in pn_util.pre_set(p):
return False
if t2 not in pn_util.post_set(
p): # redundant check, just to be sure...
return False
return True
def _get_src_transition(sub_net):
for t in sub_net.transitions:
if len(pn_util.pre_set(t)) == 0:
return t
return None
def choice_requirement(t1, t2):
return t1 != t2 and pn_util.pre_set(t1) == pn_util.pre_set(
t2) and pn_util.post_set(t1) == pn_util.post_set(t2) and len(
pn_util.pre_set(t1)) > 0 and len(pn_util.post_set(t1)) > 0
def concurrent_requirement(t1, t2):
if t1 == t2: # check if transitions different
return False
if len(pn_util.pre_set(t1)) == 0 or len(pn_util.post_set(t1)) == 0 or len(
pn_util.pre_set(t2)) == 0 or len(pn_util.post_set(
t2)) == 0: # not possible in WF-net, just checking...
return False
pre_pre = set()
post_post = set()
for p in pn_util.pre_set(t1): # check if t1 is unique post of its preset
pre_pre = set.union(pre_pre, pn_util.pre_set(p))
if len(pn_util.post_set(p)) > 1 or t1 not in pn_util.post_set(p):
return False
for p in pn_util.post_set(t1): # check if t1 is unique pre of its postset
post_post = set.union(post_post, pn_util.post_set(p))
if len(pn_util.pre_set(p)) > 1 or t1 not in pn_util.pre_set(p):
return False
for p in pn_util.pre_set(t2): # check if t2 is unique post of its preset
pre_pre = set.union(pre_pre, pn_util.pre_set(p))
if len(pn_util.post_set(p)) > 1 or t2 not in pn_util.post_set(p):
return False
for p in pn_util.post_set(t2): # check if t2 is unique pre of its postset
post_post = set.union(post_post, pn_util.post_set(p))
if len(pn_util.pre_set(p)) > 1 or t2 not in pn_util.pre_set(p):
return False
for p in set.union(pn_util.pre_set(t1),
pn_util.pre_set(t2)): # check if presets synchronize
for t in pre_pre:
if t not in pn_util.pre_set(p):
return False
for p in set.union(pn_util.post_set(t1),
pn_util.post_set(t2)): # check if postsets synchronize
for t in post_post:
if t not in pn_util.post_set(p):
return False
return True