private boolean backtrack()
    {
        // if B = bottom_of_stack
        if (bp == 0)
        {
            //  then fail_and_exit_program
            return true;
        }
        else
        {
            // B0 <- STACK[B + STACK[B} + 7]
            b0 = data.get(bp + data.get(bp) + 7);

            // P <- STACK[B + STACK[B] + 4]
            ip = data.get(bp + data.get(bp) + 4);

            return false;
        }
    }
private boolean backtrack()
    {
        
        if (bp == 0)
        {
            
            return true;
        }
        else
        {
            
            b0 = data.get(bp + data.get(bp) + 7);

            
            ip = data.get(bp + data.get(bp) + 4);

            return false;
        }
    }
private boolean backtrack ( ) { // if B = bottom_of_stack if ( bp == 0 ) { //  then fail_and_exit_program return true ; } else { // B0 <- STACK[B + STACK[B} + 7] b0 = data . get ( bp + data . get ( bp ) + 7 ) ; // P <- STACK[B + STACK[B] + 4] ip = data . get ( bp + data . get ( bp ) + 4 ) ; return false ; } }
Backtracks to the continuation label stored in the current choice point frame, if there is one. Otherwise returns
a fail to indicate that there are no more choice points, so no backtracking can be done.

@return <tt>true</tt> iff this is the final failure, and there are no more choice points.
Backtracks to the continuation label stored in the current choice point frame if there is one . Otherwise returns a fail to indicate that there are no more choice points so no backtracking can be done .