Checking and diagnostic tests for conjunctors, disjunctors, and invertors / *K. A. Popkov.* // Vestnik Moskovskogo Universiteta. Seriya 1. Matematika. Mekhanika. 2014. № 6. P. 40-45
[Moscow Univ. Math. Bulletin. Vol. 72, N 2, 2017. P. 0].

We examine problems of operability checking and state diagnosis of $N$ functional elements
realizing given Boolean function
*f*∈{x_{1}&…&x_{n},
x_{1}∨…∨*x _{n},
x_{1}}
in their perfect states and including not more than k faulty elements
by means of composition of one-output circuits from them and observation of values produced
by these circuits on any value set of input variables. Arbitrary constant faults on outputs
of functional elements are permitted. One has to minimize the number of circuits required
for operability checking and determination of states of all elements. Lower bounds of the form
ck(log_{2}N-log_{2}k) are obtained for the number of indicated circuits.*

*Key words*:
functional element, fault, circuit, check test, diagnostic test.