A/D selects a letter, W/S changes its number, and RETURN checks the inscriptions. You have five attempts. An assignment with duplicated numbers cannot be correct.
Directions work on the keyboard or pad; the pad button also acts as RETURN. SPACE opens confirmation to restart this stage. NO is selected initially. Choose with A/D, confirm with RETURN, or cancel with SPACE. Play pauses during confirmation. CTRL+C returns to BASIC.
Inscriptions sit within stone frames. Numbers turn through intermediate shapes with sound. Conditions are checked individually, leaving their results in place. Wait for the animation to finish before pressing again.
Use the A+B, B+C, and C+D sums on the left, plus the greater/less relationship between A and D. After a test, a star marks a satisfied condition and X marks a failed one.
