Puzzle Corner

[Black Hole]

After the bottom row and one other 5 I was stuck again.

Yes, and I haven't had the energy to look longer.

 

[Black Hole]

 

[EEPhil]

Yes, and I haven't had the energy to look longer.

Neither have I. Too hot and it’s making me feel unwell. Might try the second one first and then try first again. Probably tomorrow.

 

[prpr]

Pending? After the bottom row and one other 5 I was stuck again.

I did it without too much trouble, and I don't think I even had to write anything down.

 

[Black Hole]

I did it without too much trouble, and I don't think I even had to write anything down.

 

[EEPhil]

I did the Sunday one easily. Still can't make progress with the Saturday one. Must be missing something, but I can't see it.

 

[Black Hole]

OK, on the fourth sitting (I was operating at a disadvantage over the weekend) I spotted an error in my markup which should present a solution (posted on the fly):

Spoiler

D5=5 E5=3 B5=1 C2=5
[D2 D3]=[1 2] ∴︎ [A4 D4 E4]=[3 4 5] ∴︎ B4=2 C4=1 A1=1 A2=4 A3=3 A4=5...

My solution requires a double inference, so I'll grade it Hard.

 

[EEPhil]

I'll look at that. Often I can't see it even with the hints. We shall see...later.

 

[EEPhil]

Okay, done it now. Wasn't helped by me missing something similar to what I'm about to mention! Not sure I follow your logic in the spoiler though.a4,d4,e4 can't all be 3,4,5. One can't be 5 and another can't be 3 because of previous moves.

 

[Black Hole]

Not sure I follow your logic in the spoiler though.a4,d4,e4 can't all be 3,4,5. One can't be 5 and another can't be 3 because of previous moves.

That's not what my notation is intended to mean.

[A4 D4 E4]=[3 4 5] means squares A4, D4, and E4 all contain some subset of 3, 4, and/or 5 – which is a sufficient condition to conclude that B4 and C4 (the remaining squares in that particular row or column) cannot be 3, 4, or 5.

 

[EEPhil]

That's not what my notation is intended to mean.

No wonder it made no sense to me!

 

[Black Hole]

No wonder it made no sense to me!

I'm not familiar with set union symbols and such like, perhaps you can suggest a suitable symbol?

 

[EEPhil]

I'm not familiar with set union symbols and such like, perhaps you can suggest a suitable symbol?

Neither am I. That was one part of maths that made no sense to me. All those symbols such as A with missing bar, combined 0 and x ... all meaningless to me. And as for the stuff in [] . I was good at maths until half way through A level, and then my understanding took a nose dive! (That wasn't too helpful with wave equations requiring div, grad, and curl operators either. )

 

[Black Hole]

I was good at maths until half way through A level, and then my understanding took a nose dive! (That wasn't too helpful with wave equations requiring div, grad, and curl operators either. )

Very similar here. The more abstract it became, the less I was able to relate to it. I might actually do better now.

 

[EEPhil]

I might actually do better now.

It’s possible. I can remember having real difficulties at A level with the concept of resolving forces. Once I’d cracked it I found it dead easy. Probably even now, if I put my mind to it, I might make sense of the more abstract stuff. Or perhaps not.

 

[Black Hole]

Moderate--

Spoiler

C3 A2 B2 E2 & A3 are gimmies
[A1 A4] →︎ A5...

 

[EEPhil]

I found that one easy, not moderate!

 

[Black Hole]

I graded it moderate-- (minus minus) because it requires an inference. I was tempted to call it easy, but I haven't really standardised on a rating scale.

Let's call this easy as well then:

 

[EEPhil]

I'd call that more difficult than yesterday's. It looked easy, but somehow I ended up with two 4s on one line and two 5s on another. Started again and didn't make the same mistake. Yesterday, no mistakes!

 

[prpr]

Let's call this easy as well then

No, I wouldn't agree. Definitely on the way towards moderate.