jonsen

45 ms·

511.
by jonsen 8y ago
Rearranging operands with their operations is commuting. Rearranging parentheses is associating. Yes, floating point operations are also not in general associative.
512.
by jonsen 8y ago
a + b commutes all right, but some-start-value +a +b ... +x does not necessarily.
513.
by jonsen 8y ago
I think you are confusing commutativity in general with commutativity of binary operations.
514.
by jonsen 8y ago
(small number)+(small number)+ ... +(small number)+(much bigger number) may not give the same result as (much bigger number)+(small number)+(small number)+ ... +(small number)
515.
by jonsen 8y ago
Loop invariant checking should assert that if the invariant is true before the loop starts, it will also be true at the end of the loop . That’s not a general capability of assert constructs.
516.
by jonsen 8y ago
“Can you write code to reverse a linked list in place?” “Sure, I’ll just implemment a loop according to this invariant ... “ Would be nice to have the invariant ready then.
517.
by jonsen 8y ago
How would write an assert for the sum loop invariant?
518.
by jonsen 8y ago
You are merging the invariant with the variant . The loop invariant is supposed to tell about the state of the variant at any loop start. The variant in this case is the tupple (i,sum). Your version does not say anything about the stepwi
519.
by jonsen 8y ago
Cornell: http://www.cs.cornell.edu/courses/cs2110/2017sp/online/loops... https://www.cs.cornell.edu/courses/cs1110/2018sp/materials/l... CMU: https://www.c
520.
by jonsen 8y ago
Cute force
521.
by jonsen 8y ago
Would you rather they showed mating between parents and offspring? I think it’s quite normal for animal flocks to start off from a single pair.
522.
by jonsen 8y ago
Obligatory ref.: https://en.m.wikipedia.org/wiki/How_to_Read_a_Book
523.
by jonsen 8y ago
I got a pretty good idea from skimming the FriCAS book: http://fricas.sourceforge.net/doc/index.html
524.
by jonsen 8y ago
“I can’t find COBOL” I said to my wife. She replied “Well COBOL programmers don’t have any problems. No need to ask on SO where that comma should be placed. And they are so happy in their job they have no need to promote themselves on Githu
525.
by jonsen 8y ago
I really need to dig into some proper functional programming at some point! As absolutely suitable for self study I would recommend: https://www.amazon.com/Elements-ML-Programming-ML97-2nd/dp/0...
526.
by jonsen 8y ago
Please note that these are just a sample; there are plenty we didn’t include (in order to make this a blog post and not a book ).
527.
by jonsen 8y ago
Effectively they are also grounding untrained pilots.
528.
by jonsen 8y ago
https://en.m.wikipedia.org/wiki/Diode–transistor_logic
529.
by jonsen 8y ago
Problem is when some text copied and pasted here incidentally starts paragraphs with two or more spaces. And maybe the the commenter does not know why it formats weirdly.
530.
by jonsen 8y ago
Formatted for mobile: According to Richard Bellman, who came up with the name: An interesting question is, Where did the name, dynamic programming, come from? The 1950s were not good years for mathematical research. We had a very interesti
531.
by jonsen 8y ago
Interesting concept, Primer. Just a note: Scrolling is rather erratic on my iPad.
532.
by jonsen 8y ago
Maybe they build a fast flying car in the past weekends.
533.
by jonsen 8y ago
It goes further back than that: https://en.wikipedia.org/wiki/Simula
534.
by jonsen 8y ago
“What if that’s not the point?” Euclid will turn in his grave.
535.
by jonsen 8y ago
There’s no permanently dark side of the moon. The moon rotates with respect to the sun. The rotation is synchronised —due to tidal forces— with its orbital period around the earth. Therefore we see the moon as non-rotating.
536.
by jonsen 8y ago
Would like to try the app. Downloadet it. Have to sign up for an account. Will sleep on that.
537.
by jonsen 8y ago
But it has to be done the right way. "What may surprise you are the implications for teaching that follow. You'll learn why it's more useful to view the human species as bad at thinking rather than as cognitively gifted.&qu
538.
by jonsen 8y ago
Prefix name: giga Prefix symbol: G Unit name: pascal Unit symbol: Pa https://en.m.wikipedia.org/wiki/International_System_of_Unit...
539.
by jonsen 8y ago
And those who can neither do, nor teach, rebel.
540.
by jonsen 8y ago
Yes, the 6809 could jump and branch relative to the current location, program counter + offset. If all jumps where of that kind a program could be located anywhere in memory.

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