A Pansystems Extremum Algorithm for Attribute Reduction Based on Discernibility Matrix

Latent fingerprints having a latency of several weeks are applied to paper substrates using compositions comprising trimeric aliphatic acids of at least 30 carbon atoms which are substantive to paper fibers are substantially non-volatile, and are non-hardening, non-toxic and non-hygroscopic. The latent fingerprints are developed as desired by dusting in the conventional manner with toner particles, suitably, comprising magnetic particles in oleophilic matrix.