Jay

1,378 reputation

615

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	location	Minneapolis, MN
	age	64
visits	member for	2 years, 2 months
	seen	9 hours ago
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I am interested in closure systems. I think of them as generalizations of the convex hull operation rather than a generalization of closure in topology. See: http://www.ams.org/meetings/sectional/1058-52-28.pdf

	1,378 reputation	bio	website		visits	member for	2 years, 2 months
615 badges		location	Minneapolis, MN		seen	9 hours ago

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10h	comment	Why don't we define “imaginary” numbers for every “impossibility”? @AlexsandrDubinsky Check out the surreal numbers.
Jun 14	reviewed	No Action Needed Explanation of why $\frac{d}{dx} e^x=e^x$
Jun 7	reviewed	No Action Needed How many even numbers can you form which are greater than 100 subject to the following constraints?
May 30	answered	Proving that $\mathbb{Z}$ is not a field.
May 28	awarded	Convention
May 17	awarded	Constituent
May 17	comment	Another version of recursion theorem If you show us what you have tried perhaps someone can use your work to provide a more appropriate hint.
May 14	awarded	Caucus
May 14	awarded	Custodian
May 14	reviewed	No Action Needed Question about Probabilities
May 14	comment	Why is 'abuse of notation' tolerated? @MJD Abuse of notation is a recursive process. We can abuse abuses of notation!
May 11	accepted	Are there logarithm functions for arbitrary rings?
May 9	comment	Are there logarithm functions for arbitrary rings? In this question there is a method of providing an order for a ring.
May 8	comment	Are there logarithm functions for arbitrary rings? Deleted that example. I just wrote some minimal requirments. If something else is needed that's fine.
May 8	revised	Are there logarithm functions for arbitrary rings? Deleted an incorrect example.
May 8	asked	Are there logarithm functions for arbitrary rings?
Apr 30	revised	Concise formulation of lattice equalities I suggested an alternate symbol for the join operation.
Apr 29	answered	Concise formulation of lattice equalities
Apr 24	comment	find maximum and minimum for any function Are there other restrictions? Saw-tooth functions with domain $
Apr 20	awarded	Yearling