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snu-sf-class / pl2015spring

SNU 4190.310, 2015 Spring
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ASSINGMENT 10 #157

Open HyeongMee opened 9 years ago

HyeongMee commented 9 years ago

Hi!

  1. I heard from professor that he had delayed the delay due of homework 10, 11, 12, but I can't find any official notice about that. Could you tell me where I can find a notice about it? (It's really delayed, right?)
  2. What's the meaning of PAR .... END? paranthesis?

THANKS.......TT

jaewooklee93 commented 9 years ago

PAR c1 WITH c2 END is a parallel execution. It means executing two programs c1,c2 at the same time. However, you can't determine the execution order of two programs. For example, the parallel program

X=0;
Y=X;
WITH
X=1;

has multiple possible final results. The following three cases are all feasible.

X=0; Y=X; X=1; // X=1, Y=0

X=0; X=1; Y=X; // X=1, Y=1

X=1; X=0; Y=X; // X=0, Y=0

Assignment asked you to prove the existence of possibility of specific cases.