Area of a circle as follows. Draw a perpendicular from the center to the midpoint of a side of the polygon; its length, "h", is less than the circle radius. Also, let each side of the polygon have length "s"; then the sum of the sides, "ns", is less than the circle circumference. The polygon area consists of "n" equal triangles with height "h" and base "s", thus equals ⁄"nhs". But since "h" < "r" and "ns" < "c", the polygon area must be less than the triangle area, ⁄"cr", a contradiction. Therefore, our supposition that "C" might be greater than "T" must be
Straight-line grammar definition of the more general formalism of straight-line context-free tree grammars can be found in Lohrey et al. An SLG in Chomsky normal form is equivalent to a straight-line program. Straight-line grammar A straight-line grammar (sometimes abbreviated as SLG) is a formal grammar that generates exactly one string. Consequently, it does not branch (every non-terminal has only one associated production rule) nor loop (if non-terminal "A" appears in a derivation of "B", then "B" does not appear in a derivation of "A"). Straight-line grammars are widely used in the development of algorithms that execute directly on compressed structures (without prior