式8: "x" equals 2cosine "a" left brace, 0 less than "y" less than sin "a" , right bracex=2cosa0<y<sina
8
式9: "x" equals 2cosine "b" left brace, 0 less than "y" less than sin "b" , right bracex=2cosb0<y<sinb
9
式10: left parenthesis, "x" minus "t" , right parenthesis left parenthesis, sin "a" , right parenthesis equals left parenthesis, "y" , right parenthesis left parenthesis, 2cos "a" minus "t" , right parenthesis left brace, "t" less than "x" less than 2cos "a" , right bracex−tsina=y2cosa−tt<x<2cosa
10
式11: left parenthesis, "x" minus "t" , right parenthesis left parenthesis, sin "b" , right parenthesis equals left parenthesis, "y" , right parenthesis left parenthesis, 2cos "b" minus "t" , right parenthesis left brace, "t" greater than "x" greater than 2cos "b" , right bracex−tsinb=y2cosb−tt>x>2cosb
11
式12: left parenthesis, 2cos "a" , 0 , right parenthesis2cosa,0
12
式13: left parenthesis, 2cos "b" , 0 , right parenthesis2cosb,0