  Generally, negation-limited inverters problem is known as a puzzle of
constructing an inverter with AND gates and OR gates and a few inverters. In
this paper, we introduce a curious new result about the effectiveness of two
powerful ATP (Automated Theorem Proving) strategies on tackling negation
limited inverter problem. Two resolution strategies are UR (Unit Resulting)
resolution and hyper-resolution. In experiment, we come two kinds of automated
circuit construction: 3 input/output inverters and 4 input/output BCD Counter
Circuit. Both circuits are constructed with a few limited inverters. Curiously,
it has been turned out that UR resolution is drastically faster than
hyper-resolution in the measurement of the size of SOS (Set of Support).
Besides, we discuss the syntactic and semantic criteria which might causes
considerable difference of computation cost between UR resolution and
hyper-resolution.
