Activity Chart Checks : (C3123) Elements containing a truth table with illegal combination of inputs

(C3123) Elements containing a truth table with illegal combination of inputs

Error In:
Correctness
Description:
Elements described by truth tables use the same element twice as an input, via aliases.
Example:
The following figure shows the truth table definition for activity ACT_1. DATA_1 is defined to be an integer. AL_DATA_1 is defined to be an alias of DATA_1. An error is generated because DATA_1 is the same as AL_DATA_1.
Erroneous Elements:
Subroutines, actions, and activities