Seven arrangements, one routine, and the two that hold
Every row is the same three steps: write down one row per contact — the moment of its normal about the origin, then the normal itself — take the convex hull of those rows, and ask whether the origin is inside it. The parts differ, the numbers of contacts differ, and the routine does not. Two of the seven hold. The other five leave the part something, and the interesting column is what: four rays of rotation for the pinwheel, a translation straight out of the vee, and for the last two a whole *line* rather than any number of rays, which is what a rank below three means and is the case a reader has to be warned about. Note that the four contacts of the second row are the four of the first row, on the same four edges of the same square, at the same distance along each. positioned by solving, not by drawing.
A constraint that only pusheswide
Where it is used
- A constraint that only pushes Contacts that only push
- What one contact forbids Contacts that only push
- Four in the plane and seven in space Contacts that only push
- The test is a program, not a rank Contacts that only push
- The escape is a place Contacts that only push
- Free to turn and unable to Contacts that only push
- The contact that is free not to touch Contacts that only push
- Free at every instant and going nowhere Contacts that only push
- Which way it comes out Contacts that only push
- Neither part comes out first Contacts that only push
- Held is not located Contacts that only push
- Six things a hold is not Drawn wrongly
- A cone has no size Contacts that only push
- Six hold nothing Contacts that only push
- Which contact to make accurately Contacts that only push
- The hold is in the corners Contacts that only push
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