[FOM] Type-Occurrence-Token

[John Corcoran]

Consider, e.g., the word 'letter'.  In one sense there are exactly
twenty-six letters (letter-types or ideal letters) in the English
alphabet and there are exactly four letters in the word-type 'letter'.
There is exactly one word (word-type) spelled el-ee-tee-tee-ee-ar and
that word is 'letter'. In another sense of the word 'letter', there are
exactly six letters (letter-repetitions or letter-occurrences) in the
word-type 'letter'. There are two occurrences of the letter-type't' in
the word-type 'letter'.  In yet another sense, every new inscription
(act of writing or printing) of 'letter' brings into existence six new
letters (letter-tokens or ink-letters) and one new word (word-token)
that had not previously existed.  The number of letter-occurrences
(occurrences of a letter-type) in a given word-type is the same as the
number of letter-tokens (tokens of a letter-type) in a single token of
the given word.  There are no tokens of  't' in the word-type 'letter'
and there are no occurrences of 't' in a token of 'letter'. Many
logicians fail to distinguish "token" from "occurrence" and a few
actually confuse the two concepts. The word 'instance' is often used
ambiguously: now for "token", now for "occurrence".
In the above paragraph-type there are nineteen occurrences of the
word-type 'letter' and, as usual, no sentence-type occurs more than
once. The token of that paragraph that you just looked at is not the
token that I am now looking at. But we were both thinking about the same
paragraph type.

Q1. Can you cite any articles or books by yourself or others that make
this three-way distinction giving three technical terms? 
Q2. The type-token distinction is often attributed to Peirce in 1906. Do
you know any reason to doubt this?
Q3. Have you seen the type-occurrence distinction attributed to anyone?
Q4 Do you know of anything of a historical or philosophical nature on
the token-occurrence distinction?
Q5.Have you noticed anything that could be regarded as a mistake
involving failure to make this three-way distinction?
Q6. Do you have any thoughts on this distinction that you would care to
share?
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