表达式22: polygon left parenthesis, "G" , right parenthesispolygonG
22
表达式23: "l" Subscript, "i" "n" "e" , Baseline equals left parenthesis, 1 minus "t" , right parenthesis "G" left bracket, "i" , right bracket plus "t" "G" left bracket, "i" plus 1 , right bracket for "i" equals left bracket, 1... "G" .length minus 1 , right bracketline=1−tGi+tGi+1fori=1...G.length−1
00
定义域t最小值：
less than or equal to "t" less than or equal to≤t≤
