> as lemmas
slope-line
slope-line n.
Brit. 
/ˈsləʊplʌɪn/
, /ˈsləʊplʌɪn/U.S. /ˈsloʊpˌlaɪn/
/ˈsloʊpˌlaɪn/Π
1712 J. James tr. A.-J. Dézallier d'Argenville Theory & Pract. Gardening 67 The Turf must be laid so that..the Slope-line be kept without Elbows and Inequalities.
1859 A. Cayley Coll. Math. Papers IV. 108 A system of contour lines and steepest or slope lines.
<
as lemmas