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Index Finder

Routine Summary Inputs Outputs Author
Returns the index number of an element searched for within a list X - Element that it's finding
L₁ - List that's being searched
N - The occurrence to search for
Ans - Index number of element searched. RogueBantha, CubeBag
//Finds first occurrence of X in L₁
1+sum(not(cumSum(L₁=X

//Finds last occurrence of X in L₁
max((L₁=X)cumSum(1 or L₁

// Finds the Nth occurrence of X in L₁
1+sum(N>cumSum(L₁=X

Given a value in X, this code will search L₁ and return the index number of the desired occurrence of X.

Error Conditions

If L₁ does not contain X, the first and third routines will both return 1+[dim(](dim.html)L₁); the second will return zero.

Authors: KG