how i tell category ability open set (.net)?

i have this:

public twine log
        {
            { relapse log; }
            stable set
            {
                (log != value)
                {
                    markmodified(propertynames.log, log);
                    record = value;
                }
            }

        }

and concentration category databinding does this:

propertyinfo pi = reflectionhelper.getpropertyinfo(boundobjecttype, sourceproperty);

if (!pi.canwrite)
                setreadonlycharacteristics(boundeditor);

but propertyinfo.canwrite does caring presumably set publicly accessible, wholly exists.

how i establish there's public set, only any set?