When a leg analysis is performed, CodeCalc reads entire data from the structural database (AISC89.BIN). The resulting leg loads are compared to the allowable leg compression loads as outlined in AISC paragraph 1.5.1.3. Either the Kl/r > Cc or Kl/r < Cc formula will be shown as appropriate. The combination of stresses due to bending and compression will be compared to the allowable per AISC 1.6.1. This is generally termed the AISC unity check. If the result is greater than 1.0, it implies that the member has failed.