Having defined"abnormality"

[the arrow of egypt]

In the name of the Merciful Allah,
Hi, please read thiis"Having defined "abnormality", we then provide some basic information about ......".I'm asking about the first phrase, is there something latent?, and what is it?. How a sentence like "Having defined" abnormality" grammaticaly be like that?

[Casiopea]

Having (once) defined "abnormality", we then provide ... .
(once) Having defined "abnormality", we then provide ... .

Does that help?

[the arrow of egypt]

The author in the context tell what he is going to do in the next pages. So, you think the phrase could be" as soon as having defined "abnormality", we then .............". May I ask, cosidering "defined" as an adjective where is the indefinite article before it? Also,if it was"once", shouldn't we say " we'll then provide..."?

[the arrow of egypt]

I'm asking this again, please explain to me how a sentence as the one in red be grammatically like that, and " having" here referes to whom? Is there something latent? what is this? If it is " once"as Casiopea said, shouldn't we say " we will then provide...."? If it " once", isn't latency supposed to be used only to avoid redundancy?
Here is the passage that include the sentence- in red- I'm asking about:This chapter sketches the outlines of the field of abnormal psychology and the varied training and activities of the people who work in it. First, however, we cover the ways in which abnormal behavior is defined and classified so that researchers and mental health professionals can communicat with each other about the people they see. Some of the issues here are probably more complex and controversial than you might expect. Having defined "abnormality",we provide then some basic information about the extent of behavioral abnormalities in the population at large.
Please, every body who knows what I'm asking about for sure give help.

[engee30]

I'm asking this again, please explain to me how a sentence as the one in red be grammatically like that, and " having" here referes to whom? Is there something latent? what is this? If it is " once"as Casiopea said, shouldn't we say " we will then provide...."? If it " once", isn't latency supposed to be used only to avoid redundancy?
Here is the passage that include the sentence- in red- I'm asking about:This chapter sketches the outlines of the field of abnormal psychology and the varied training and activities of the people who work in it. First, however, we cover the ways in which abnormal behavior is defined and classified so that researchers and mental health professionals can communicat with each other about the people they see. Some of the issues here are probably more complex and controversial than you might expect. Having defined "abnormality",we provide then some basic information about the extent of behavioral abnormalities in the population at large.
Please, every body who knows what I'm asking about for sure give help.

I would call the style of the languge used in the extract 'an instructional language', similar to the so-called 'historic present'. It's like giving instructions for making a cake from a recipe - in such cases we use the Present Simple tense.
Having defined 'abnormality'... = Once we have defined 'abnormality'... - the former is a non-finite clause, while the latter is a finite-clause.
___________________________
NOTE:
Bear in mind I'm not a teacher!

[the arrow of egypt]

Thanks Engee, now I'm more positive about the meanining that Casiopea mentioned. But I didn't understand yet the underlying rules behind this unfamiliar phrase.

[engee30]

Thanks Engee, now I'm more positive about the meanining that Casiopea mentioned. But I didn't understand yet the underlying rules behind this unfamiliar phrase.

You can use different ways to express yourself. And that usage is one of the possible ways we have. It's all grammar.
As I wrote in one of my previous posts in this thread, the verb phrase 'Having defined' is part of the non-finite clause 'Having defined 'abnormality'. The difference between using a non-finite clause and a finite clause lies in what we want to, and in our case, what we don't want to express - it's not necessary to say who defines abnormality, the message of the text with the subsequent process(es) explained are easy to understand.
What about the tense used in the clause?
Well, all I can say is that using the perfect infinitive in a continuous form is just to emphasise that one action took place before another.

I hope I've been more 'explicit' than the non-finite clause itself!

[the arrow of egypt]

[Red5]

This might also be of interest: http://www.usingenglish.com/weblog/archives/000005.html