Failure to properly constrain intermediate signals Failure to constrain output signals in instantiated templates Failure to constrain divisors in division operations to nonzero values Use of BN254-specific templates from Circomlib with a different curve Failure to properly constrain inputs to Circomlib’s LessThan circuit To understand the subtleties of the implementation of the LessThan template, let’s first consider the expected use case when both inputs to LessThan are at most n bits, where n is small enough to ensure that both inputs are nonnegative. The latest version of Circomspect identifies locations where a template is instantiated but the output signals defined by the template are not constrained.