[NTG-context] setupinterlinespace top and height relations

hi all, As a grid system fetishist, I would like to align the top of my first line with the top of the layout frame. Using try and error (still a context newbie) I managed this by "\setupinterlinespace [height=.5, top=.7]". this seems strange to me, because i was expecting that the argument top is the only one that controls \topskip. Is there a graphic that shows the relation between the arguments of setupinterlinespace? best michael \setupbodyfont [palatino, 10pt] \setupinterlinespace [height=.5, top=.7] \showframe \starttext \beginofshapebox \input zapf \endofshapebox \reshapebox{\hbox{\red\ruledhbox{\black\box\shapebox}}} \flushshapebox \stoptext