404 forum

Discussion about 404

Back to the main 404 site

You are not logged in.

Announcement

  • Please do not post direct solutions to puzzles, but rather post hints as appropriate
  • Type [spoiler] ... [/spoiler] around the outside of any hints so they can't be read by accident - e.g. [spoiler]have you tried looking at the corner of the page?[/spoiler]

#1 2019-12-31 03:39:59

kaarterdme
Member
Registered: 2019-11-26
Posts: 7

Interpreting symbols

Can someone help me with this one?

I'm having trouble understanding the symbols. 

The hints say that

Spoiler

For ’+’, combine lit elements (logical OR)
For ’–’, remove lit elements (logical XOR)
For ’&’, find elements in both the first and the second input (logical AND)

Can someone explain this to me?

Do I have to know

Spoiler

computer science?

Do I have to teach myself

Spoiler

Boolean Algebra?

Offline

#2 2020-01-05 02:10:12

kite
Member
Registered: 2019-11-29
Posts: 12

Re: Interpreting symbols

I (Kite's husband) work in the field you mentioned, and I found this one confusing.  The concepts in the puzzle are used in that field, but the operators (symbols) in the puzzle aren't standard; perhaps the authors thought they'd be more intuitive for laypeople.

Spoiler

For each operator, you'll need to combine two glyphs to create a new glyph.  Here, I'm using 'glyph' to describe the image created by the 7-segment displays.  The initial glyphs across the top of the page all look like digits, but your intermediate results may not look like anything meaningful.

Spoiler

For '+': if a given segment is lit in at least one of the input glyphs, it should be lit in the output glyph.
For '-': start with the input glyph that has more segments lit, then remove whatever segments are lit in the other input glyph. (The way I've described this is more consistent with their use of '-' as the operator and 'remove' as the hint, but not really the same as 'XOR', although they happen to work out the same in this puzzle.)
For '&': if a given segment is lit in BOTH of the input glyphs, it should be lit in the output glyph.

Also, I found it helpful to draw arrows on some of the lines to make it clear which way they're going.

Offline

#3 2020-01-05 05:41:59

kaarterdme
Member
Registered: 2019-11-26
Posts: 7

Re: Interpreting symbols

THANK YOU!

You gave me the final piece I needed!

I already looked up a bit about

Spoiler

logic gates

but I was trying to apply it to the

Spoiler

numbers! Not segments!

THANK YOU SO MUCH!

Offline

#4 2020-01-07 18:07:20

Alex55
Member
Registered: 2019-11-18
Posts: 121

Re: Interpreting symbols

Can anyone explain it, for those who have these kind of knowledge?

Offline

Board footer

Powered by FluxBB