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===Sieventäminen Karnaugh'n kartalla**KESKEN**===
===Sisääntuloarvojen järjestys===
On a K-map, the order in which the input values combinations are placed is of outmost importance. By looking at the example image above, it can be noticed that it doesn't use the normal, or numeric, ordering of values (00, 01, 10, 11), but instead uses (00, 01, 11, 10). Although there are usually many orderings that can be used, not all possible orderings are usable for a K-map. A formal description for valid K-map orderings would be defined by the following rules:
# The input values combinations at two adjacent rows or columns must differ in exactly one bit.
# The map is ciclic: the first and last rows are considered to be adjacent, and the first and last columns are also adjacent.
# Each possible combination of bits must appear exactly once in the map.
For two-variable maps, fulfilling this rules is trivial: one of the variables is assigned to rows, the other one to columns, and a 2x2 map can be drawn where both possible sequences (0,1 and 1,0) are valid. It's valid even to use (0,1) for one variable and (1,0) for the other. On three or four variables, either the columns or rows (or both, for 4 variables) need to hold two variables. The sequence used in the examples above (00, 01, 11, 10) works well, and is the most used; an alternative to this could be (00, 10, 11, 01). If a K-map is ever needed for a 5 or even more inputs circuit, then longer sequences need to be made up that fulfill the rules above. For three variables (8 combinations), the (000, 001, 011, 010, 110, 111, 101, 100) sequence is often used. This is enough for maps of up to 6 inputs, or 64 combinations; bigger circuits are very rarely mapped by hand, most often using specialized software to build the map and even to retrieve information from it; but, if the need arises, an appropriate combinations sequence can be made by [[w:Gray_code#Constructing_an_n-bit_gray_code|constructing an n-bit Gray Code]].
As could be noticed from later sections, optimization of circuits through K-maps relies completely in the above rules or properties of such maps, so using wrong combination sequences may lead to circuits that are not optimal, or even to circuits that do not produce the expected output.
==Simplification of a Boolean Equation or Truth Table==
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