# Clarification for a class of Turing machine problems

So say I have a task like this:

Construct a Turing machine transforming the word u to the word v byt removing all the sequences of form "ba" from the word u. Input alphabet = {a,b,c}.

Example: for IN cabbaacba, OUT cac.

And my problem always is: can I leave blank characters in place of "ba" sequences in tasks like this so that in the end, I have something like $ca \Phi \Phi \Phi \Phi c \Phi \Phi$ on the tape or do I have to work on the tape in such a way that I end up with, for example "cac", written consecutively, without blanks?

-
The specification does not say that you can have spaces between the symbols in the output word. Is the blank character even in the output language? –  Dave Clarke Jan 30 '13 at 13:49
I don't know, that's all the spec I have. If it doesn't explicitly state the output language, couldn't I just create my own by using the input one + blank symbol? –  Straightfw Jan 30 '13 at 13:56
But that doesn't seem to answer the question. The question does not mention replacing "ba" by spaces. –  Dave Clarke Jan 30 '13 at 14:04
I see. So it seems in such tasks I'd just have to find a way to leave only the desired characters. Thank you, then! :) –  Straightfw Jan 30 '13 at 14:05
@Dave Write it as an answer? –  Yuval Filmus Jan 30 '13 at 16:23