moderator writes:
>But what's a T diagram? -John]

It's a graphical way of showing what compiles what to give what in a
complex compiler bootstrapping sequence. The classic example -- and
possibly the only time T diagrams actually saw non-trivial use :-) -- is
the elaborate sequence that spreads over the endpapers of the ancient tome
"A Compiler Generator", by McKeeman, Horning, and Wortman (1970), showing
how the XPL compiler was bootstrapped.

marcia_raju@rediffmail.com writes:
>could anyone please tell me the 'bootstrapping' process in C and
>FRTRAN compilers , illustrated with T-diagrams?

That sounds like a homework question.

>But what's a T diagram? -John]

A graphical representation of a compiler, and the languages involved
in it:

source language target language
implementation language

shorter

S-T
I

The name T-diagram comes from the form of the diagram.

The typical homework or exam questions are that you are given some
compilers or interpreters in source form, and some compiler or
interpreter for a different language in executable form, and you have
to find a way to generate some goal compiler or interpreter from
that.
- anton