###########################################################
#                                                         #
#    Exercise 4.15b:                                      #
#                                                         #
#    Construct an ROBDD for a given threshold             #
#    system and evaluate its reliability                  #
#                                                         #
###########################################################

from c_robdd import ROBDDSystem
from c_threshold import ROBDDThreshold

# Component reliabilities            
p = 0.5

# Component weights
a = [2, 4, 4, 6, 6, 8]

# Threshold
b = 15

# Number of components
n = len(a)

# Sum of weights
wsum = 0
for wg in a:
    wsum += wg
    
sys = ROBDDSystem(ROBDDThreshold(a, wsum, b))

result = sys.calculateReliability0(p)
sys.printSystem()

print("")
print("System unreliability = ", result[0])
print("System reliability = ", result[1])