Douglas Blumeyer's RTT How-To: Difference between revisions
Cmloegcmluin (talk | contribs) |
Cmloegcmluin (talk | contribs) m →multivectors: use ceil |
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Now let’s see how to do the complement operation. | Now let’s see how to do the complement operation. | ||
# Find the rank, halved, rounded up. In our case, <span><math> | # Find the rank, halved, rounded up. In our case, <span><math>\lceil \frac{r}{2} \rceil = \lceil \frac{2}{2} \rceil = \lceil 1 \rceil = 1</math></span>. Save that result for later. Let’s call it <span><math>x</math></span>. | ||
# Find the lexicographic combinations of <span><math>r</math></span> primes again: (2,3), (2,5), (3,5). Except this time we don’t want the primes themselves, but their indices in the list of primes. So: <span><math>(1,2)</math></span>, <span><math>(1,3)</math></span>, <span><math>(2,3)</math></span>. | # Find the lexicographic combinations of <span><math>r</math></span> primes again: (2,3), (2,5), (3,5). Except this time we don’t want the primes themselves, but their indices in the list of primes. So: <span><math>(1,2)</math></span>, <span><math>(1,3)</math></span>, <span><math>(2,3)</math></span>. | ||
# Take the sums of these sets of indices, and to each sum, also add <span><math>x</math></span>. So <span><math>1+2+x</math></span>, <span><math>1+3+x</math></span>, <span><math>2+3+x</math></span> = <span><math>1+2+1</math></span>, <span><math>1+3+1</math></span>, <span><math>2+3+1</math></span> = <span><math>4</math></span>, <span><math>5</math></span>, <span><math>6</math></span>. | # Take the sums of these sets of indices, and to each sum, also add <span><math>x</math></span>. So <span><math>1+2+x</math></span>, <span><math>1+3+x</math></span>, <span><math>2+3+x</math></span> = <span><math>1+2+1</math></span>, <span><math>1+3+1</math></span>, <span><math>2+3+1</math></span> = <span><math>4</math></span>, <span><math>5</math></span>, <span><math>6</math></span>. | ||