More digital silliness

[David W. Wilson]

I like to distinguish between 'permutation' and 'anagram'.

For a word w in language L, a string s is a permutation of w if s and w have
the same number of each symbol they contain. A string s is an anagram of w
if it additionally belongs to w.

For example, if L is the English language, then the word 'stop' has
permutations 'ospt', 'sopt', 'spot', 'post', 'spto', etc. Of these
permutations, only 'spot' and 'post' are anagrams, since they are in L.
Think about it. In the game of anagrams, you could not play 'ospt' as an
anagram of 'spot', since 'ospt' is not a word.

Similarly, let L be the language of standard base-10 representations of
positive integers. Then L consists of the strings of 1 or more decimal
digits not starting in 0. In this language, 25600 has the permutations
20605, 06502, and 60025, but of these 06502 is not an anagram, since it is
not a standard base-10 integer representation, because it starts with 0.