LSt.9:5 :ܗܐ ܓܝܪ ܣܘܪܛܐ ܬܪܝܨܐ ܢܦ̈ܠܢ ܡܢܘ̈ܬܗ ܟܠܗܝܢ ܥܠ ܡܢܘ̈ܬܐ ܟܠܗܝܢ ܕܣܘܪܛܐ ܬܪܝܨܐ‏ : for all the parts of a straight line rest on all the parts of the straight line
See the entire entry for surṭā n.m. line