Error in Puzzle 54?


The objective in puzzle 54 is “Flip the bit specified in register A to the right”. Logically, this would mean that if A=0, then bit 0 would be flipped, if A=1, then bit 1 would be flipped, etc. However, the examples indicate the opposite, and in my opinion, counter-intuitive ordering. The examples show that if A=0, then bit 3 is flipped, if A=1, then bit 2 is flipped, etc.

Is this an error in the manual? If not, then would it make sense in future revisions of the manual to reverse the labels on the 4 decoded bits so that the value of A and the label on the bits to set match?


Yeah, it’s an error. I fixed it and in the next run it will be correct. Thanks for telling me about it!


Thank you for your confirmation. I don’t want to peek at the solution before I solve the puzzle, so can you please confirm what the actual intent of the puzzle is? Is the description correct (A=0 means bit 0 is flipped), or are the examples correct (A=0 means bit 3 is flipped)?

Thanks again for your response.


The numbers that the registers equal in the examples are wrong. It should be that if A=0, bit 0 should be flipped, and so on.