The left and right commands find the left and right parts of a list. (See Section 4.2.4, Section 7.2.3, Section 5.5.1, Section 5.6.2, Section 8.2.4 and Section 8.2.5 for other uses of left and right.)
left([0,1,2,3,4,5,6,7,8],3) |
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right([0,1,2,3,4,5,6,7,8],4) |
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