Now we collect 13 features, that will be described in original paper, except constraint representation, but it can be extended.

• stack - size of state’s current call stack.
• successor - number of successors of state’s current basic block.
• testCase - number of test cases generated so far
• coverageByBranch - number of instructions, which was covered first time on our last branch
• coverageByPath - number of instructions, which was covered first time on our path
• depth - number of forks already performed along state’s path.
• cpicnt - number of instructions visited in state's current function.
• icnt - number of times for which st ate’s current instruction has been visited
• covNew - number of instructions executed by st ate since the last time a new instruction is covered
• subpath - number of times for which st ate’s subpaths have been visited. The length of the subpaths can be 1, 2, 4, or 8 respectively