CFD Online Discussion Forums - Triangulation condition for timeVaryingMappedFixedValue

Hello World.

I'm currently trying to understand the check for a correct local coordinate system with the use of timeVaryingMappedFixedValue boundary condition.

For simplicity I will post the relevant part of the code.
The complete code is here: http://foam.sourceforge.net/doc/Doxy...8C_source.html

Code:

    const point& p0 = samplePoints[0];



    // Find point separate from p0

    vector e1;

    label index1 = -1;



    for (label i = 1; i < samplePoints.size(); i++)

    {

        e1 = samplePoints[i] - p0;



        scalar magE1 = mag(e1);



        if (magE1 > SMALL)

        {

            e1 /= magE1;

            index1 = i;

            break;

        }

    }



    // Find point that makes angle with n1

    label index2 = -1;

    vector e2;

    vector n;



    for (label i = index1+1; i < samplePoints.size(); i++)

    {

        e2 = samplePoints[i] - p0;



        scalar magE2 = mag(e2);



        if (magE2 > SMALL)

        {

            e2 /= magE2;



            n = e1^e2;



            scalar magN = mag(n);



            if (magN > SMALL)

            {

                index2 = i;

                n /= magN;

                break;

            }

        }

    }

Now my questions are:

the condition for a "pass through" seems to be
magE1 > SMALL and magN > SMALL ?
Now I haven't found any definition of what SMALL may be?
What is it? Where is it defined?
What kind of operation is e1 /= magE1 ?
What is the break command doing?
What is n = e1^e2 doing? This is not a power-operation, right?!