கணக்கீட்டு மொழியியல்

What is the process called: collection of distinct elements
Set Construction / Set Formation

Permutation → Order matters
Combination → Order does not matter
With and Without Repetition

Different permutations of letters = different lexical items

Add
Subtract (remove)
Change
Rearrange
Anagram
Reverse
Permutations

List of all possible affixes or inflections attached to a root:
Root + {plural, tense, aspect, case} = combination set

Permutations → generate possible strings
Combinations → choose subsets of letters/morphemes

PERMUTATIONS (Order Matters)

1. Without Repetition

P(n, r) = n! / (n - r)!

2. With Repetition

P_rep(n, r) = n^r

COMBINATIONS (Order Does NOT Matter)

3. Without Repetition

C(n, r) = n! / (r! (n - r)!)

4. With Repetition

C_rep(n, r) = C(n + r - 1, r)
= (n + r - 1)! / (r! (n - 1)!)

1
எ

2
Permutations of n items taken 2 at a time, with repetition:
P(n, 2) with repetition = n × n
எ×எ

3
P(n, 3) with repetition = n × n × n

26
247
எ^*

12, 18 (2)
900

5, 18 (2)
529