a <- h & reliable(s_1).
d <- c & reliable(s_1).

e <- d & reliable(s_2).
f <- k & reliable(s_2).
z <- g & reliable(s_2).
j <- reliable(s_2).

h <- d & reliable(s_3).

a <- b & e & reliable(s_4).
b <- c & reliable(s_4).

g <- f & j & reliable(s_5).

false <- a & z.
c.
k.

assumable reliable(X).