Notelife



Defter

Chronos notelife نرم افزاری برای نگهداری و دسته بندی یادداشت های شماست. نرم افزاری سبک با رابط کاربری ساده است / notelife is a premium note manager designed for the rest of us. While it goes beyond the basics, it isnt hard to use. A good storage system for IDEAS is essential. I have been able to sync with my laptop pretty easily by setting up a computer-to-computer network on my laptop, turning on wireless on my iPhone and joining the network, and then opening up NoteLife and syncking.

I was just solving some congruence problems with prime modulo. Such as this one:
[tex]x^2equiv 59(mod 11)[/tex]
I was using Quadratic Residues to determine whether or not my equations had solutions. For example, in the case above, I would write out the quadratic residues of 11:
[tex]QR_{11} = {1,3,4,5,9}[/tex]
Here I noted that if my modulo was prime then the number of quadratic residues is always less than half the prime. So in this case, 11/2 = 5.5 and there are 5 QR's.
Then I would use the Legendre symbol:
[tex](59/11) = (4/11) = 1 quadquadmbox{since 4 is a quadratic residue of 11}[/tex]
Which tells me that my equation has a solution. But notice that I needed to calculate all the quadratic residues first.
So then I came across the Quadratic Reciprocity Law which said that if p and q are primes then
[tex](p/q) = -(q/p)[/tex]
if [itex]p,qequiv 3(mod 4)[/itex], otherwise [itex](p/q) = (q/p)[/itex].
So, this tells me that solving an equation such as [itex]x^2equiv p(mod q)[/itex] is exactly the same as solving [itex]x^2 equiv q(mod p)[/itex], UNLESS p or q is congruent to 3 modulo 4.
EX1. In modulo 5, we have 1 and 4 as quadratic residues. Then (5/97) = (97/5) because neither 5 nor 97 are congruent to 3 modulo 4. So then (5/97) = (97/5) = (2/5) = -1 since 2 is not a QR of 5.
EX2. (85/97) = (5/97)(17/97) {by a corollary of the QRL} = (97/5)(97/17) {since neither 5 nor 17 are congruent to 3 modulo 4} = (2/5)(12/17) {simplifying in mod 17} = (-1)(-1) = 1. Since the QR's of 17 are 1,2,4,8,9,13,15,16, and 12 is not a QR of 17.
My question is: why is what I've written in bold true? Why aren't those two equations equivalent if p or q is congruent to 3 modulo 4? What is so special about 3 modulo 4?
Notelife

Nate Life

1.0.5 iCloud syncs can now be cancelled (Settings > Sync)
1.0.5 iCloud syncing improvements (including shorter timeouts for poor connections)
1.0.4 iPhone X compatibility including Face ID support
1.0.4 Combined font and tag controls into single keyboard toolbar to make it modeless
1.0.4 Fixed problem updating font alignment controls when no text is selected
1.0.4 Fixed handling of mute switch on device to match behavior of Apple’s apps
1.0.4 Fixed a problem where moving a note to a new folder couldn’t be cancelled
1.0.3 Redesigned the Folder List and Note List views for iOS 11
1.0.3 Important changes to improve iCloud syncing
1.0.3 The Note List includes an integrated search field—pull the Note List down to access
1.0.3 The number of notes appears in the Note List’s search field
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1.0.3 The Note Info sidebar shows the word, character and paragraph counts for the note text
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1.0.3 Settings includes sync status information and controls for manually triggering a sync, etc.
1.0.3 The app can no longer go to sleep while a large sync is running
1.0.3 The “Unfiled” folder name can now be edited
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1.0.3 When a note was being moved and the Cancel button was tapped, the Cancel button now immediately disappears
1.0.3 Fixed some problems displaying emojis in the Note List
1.0.3 Fixed a problem where the Done button in the photo viewer was obscured if there were a lot of photos attached
1.0.2 Added compatibility with iOS 11
1.0.2 Added 3D Touch Quick Action to app icon: New Note, Photo Library, Take Photo and Search
1.0.2 Photos can now be added to the Media Gallery (above the note) or inserted in the note text (Settings > General)
1.0.2 When a photo is inserted in the note text, a thumbnail now appears in the Note List
1.0.2 A search now highlights the search terms in the Note List
1.0.2 Fixed problem dismissing the Tags popover when running on an iPad
1.0.2 Redesigned the Settings view to make it easier to use
1.0.2 Fixed some problems with the note text view
1.0.2 Fixed problem with keyboard sometimes not appearing when tapping an note’s text
1.0.2 Images attached to a note are now printed at full-size instead of thumbnail size
1.0.2 Photos embedded in text resize automatically
1.0.2 Faster iCloud sync
1.0.2 Added Debug Log feature
1.0.2 Fixed problem where the app occasionally wouldn’t recognize a subscription
1.0.1 Added ability to bold the first line of new notes to signify a pseudo-title
1.0.1 Added setting to control automatic automatic bolding of first line of new notes
1.0.1 Added ability to sort notes by “title' (first line of note since notes don’t have an actual title)