Assertion: airfoil | /r/HasProperty | angularly
Facets:
value: to define a chord section
type: PURPOSE
Source sentences:
text: A further object of the invention is an airfoil of the character above having a continuous upper surface and a lower surface having a stepped discontinuity, the surfaces being angularly and spacially related to define a chord section that increases in thickness from the leading edge of the airfoil to the discontinuity.