The On-Line Encyclopedia of Bongard Problems

Search: keyword:math

Displaying 21-30 of 53 results found.

( prev | next ) page 1 2 3 4 5 6

Sort: id Format: long Filter: (all | no meta | meta) Mode: (words | no words)

There exists a closed trail that hits each edge exactly once vs. not so.

(edit; present; nest [left/right]; search; history)

	COMMENTS	`Left examples are called "Eulerian graphs."` `A connected graph is Eulerian if and only if each vertex is incident to an even number of edges.`
	CROSSREFS	`Adjacent-numbered pages: BP555 BP556 BP557 BP558 BP559 * BP561 BP562 BP563 BP564 BP565`
	KEYWORD	`precise, allsorted, math, traditional, preciseworld`
	CONCEPT	`graph (info \| search),` `distinguishing_crossing_curves (info \| search),` `all (info \| search),` `even_odd (info \| search),` `existence (info \| search)`
	WORLD	`connected_graph [smaller \| same \| bigger]`
	AUTHOR	`Aaron David Fairbanks`

There exists a closed trail that hits each vertex exactly once vs. not so.

(edit; present; nest [left/right]; search; history)

	COMMENTS	`Left examples are called "Hamiltonian graphs."`
	CROSSREFS	`Adjacent-numbered pages: BP557 BP558 BP559 BP560 BP561 * BP563 BP564 BP565 BP566 BP567`
	KEYWORD	`math, traditional`
	CONCEPT	`graph (info \| search),` `distinguishing_crossing_curves (info \| search)`
	WORLD	`connected_graph [smaller \| same \| bigger]`
	AUTHOR	`Aaron David Fairbanks`

Triangular number of dots vs. non-triangular number of dots

(edit; present; nest [left/right]; search; history)

	COMMENTS	`All examples in this Problem are groups of black dots.` `The nth triangular number is the sum over the natural numbers from 1 to n, where n > 0. Note: 0 is the 0th triangular number. The first few triangular numbers are 0, 1, 3 (= 1+2) and 6 (= 1+2+3)`
	CROSSREFS	`Adjacent-numbered pages: BP564 BP565 BP566 BP567 BP568 * BP570 BP571 BP572 BP573 BP574`
	KEYWORD	`nice, precise, allsorted, notso, number, math, left-narrow, left-null, help, preciseworld`
	WORLD	`dots [smaller \| same \| bigger]`
	AUTHOR	`Leo Crabbe`

Vertices may be partitioned into two sets such that no two vertices in the same set are connected versus not so.

(edit; present; nest [left/right]; search; history)

	COMMENTS	`Left examples are called "bipartite graphs."`
	CROSSREFS	`Adjacent-numbered pages: BP571 BP572 BP573 BP574 BP575 * BP577 BP578 BP579 BP580 BP581`
	KEYWORD	`precise, allsorted, notso, math, traditional, preciseworld`
	CONCEPT	`graph (info \| search),` `distinguishing_crossing_curves (info \| search)`
	WORLD	`graph [smaller \| same \| bigger]`
	AUTHOR	`Aaron David Fairbanks`

Graph contains a "loop" a.k.a. cycle (cyclic) versus graph is acyclic.

(edit; present; nest [left/right]; search; history)

	CROSSREFS	`Adjacent-numbered pages: BP783 BP784 BP785 BP786 BP787 * BP789 BP790 BP791 BP792 BP793`
	KEYWORD	`nice, precise, allsorted, math, traditional, preciseworld`
	CONCEPT	`graph (info \| search),` `distinguishing_crossing_curves (info \| search),` `loop (info \| search)`
	WORLD	`connected_graph [smaller \| same \| bigger]`
	AUTHOR	`Aaron David Fairbanks`

The leftmost two add (as vectors) to the right versus no two add to a third.

(edit; present; nest [left/right]; search; history)

	CROSSREFS	`Adjacent-numbered pages: BP785 BP786 BP787 BP788 BP789 * BP791 BP792 BP793 BP794 BP795`
	KEYWORD	`math, structure, orderedtriplet, traditional`
	CONCEPT	`addition (info \| search),` `2_inputs_1_output (info \| search)`
	AUTHOR	`Aaron David Fairbanks`

The leftmost two angles measured from thin line add to the rightmost versus no two angles add to a third.

(edit; present; nest [left/right]; search; history)

	COMMENTS	`This answer is independent of whether angles are measured clockwise or counter-clockwise; only a consistent choice must be made.`
	CROSSREFS	`Adjacent-numbered pages: BP786 BP787 BP788 BP789 BP790 * BP792 BP793 BP794 BP795 BP796`
	KEYWORD	`math, structure, orderedtriplet, traditional`
	CONCEPT	`addition (info \| search),` `2_inputs_1_output (info \| search)`
	AUTHOR	`Aaron David Fairbanks`

Image conceptually relates to the golden ratio/Fibonacci numbers versus not so.

(edit; present; nest [left/right]; search; history)

	CROSSREFS	`BP800 is the metaconcept page for this concept.` `Adjacent-numbered pages: BP792 BP793 BP794 BP795 BP796 * BP798 BP799 BP800 BP801 BP802`
	KEYWORD	`abstract, math, concept, experimental`
	CONCEPT	`golden_ratio (info \| search)`
	AUTHOR	`Aaron David Fairbanks`

Number pointed to on number line is "important" mathematical constant vs. not so.

(edit; present; nest [left/right]; search; history)

	COMMENTS	`This is the "harder version" of BP505.`
	CROSSREFS	`Adjacent-numbered pages: BP796 BP797 BP798 BP799 BP800 * BP802 BP803 BP804 BP805 BP806`
	KEYWORD	`hard, less, abstract, math, subjective, challenge, right-unknowable, collective, experimental, finishedexamples`
	AUTHOR	`Aaron David Fairbanks`

Image of repeating wallpaper with only 3-fold rotational symmetries versus image of repeating wallpaper with some other symmetries.

(edit; present; nest [left/right]; search; history)

	COMMENTS	`Left examples have wallpaper symmetry group p3 (a.k.a. 333).`
	CROSSREFS	`Adjacent-numbered pages: BP801 BP802 BP803 BP804 BP805 * BP807 BP808 BP809 BP810 BP811`
	KEYWORD	`nice, math, bordercontent`
	CONCEPT	`rotational_symmetry (info \| search),` `three (info \| search)`
	WORLD	`wallpaper [smaller \| same \| bigger]`
	AUTHOR	`Aaron David Fairbanks`

( prev | next ) page 1 2 3 4 5 6

		Hints
(Greetings from The On-Line Encyclopedia of Bongard Problems!)