Expression 47: "O" Subscript, 1 , Baseline tilde "f" Subscript, "o" , Baseline left parenthesis, "O" , right parenthesisO1~foO
47
Expression 48: "y" equals "f" Subscript, "o" , Baseline left parenthesis, "x" , right parenthesisy=fox
48
Expression 49:
49
Expression 50: "h" Subscript, "f" , Baseline left parenthesis, "x" , "y" , right parenthesis equals "f" Subscript, "o" , Baseline left parenthesis, "o" , right parenthesis "f" Subscript, 0 , Baseline left parenthesis, "f" Subscript, "s" "x" , Baseline left parenthesis, "o" , right parenthesis left parenthesis, "x" minus "a" , right parenthesis , "f" Subscript, "s" "y" , Baseline left parenthesis, "o" , right parenthesis "y" , right parenthesishfx,y=foof0fsxox−a,fsyoy
50
Expression 51: "f" Subscript, "f" , Baseline left parenthesis, "x" , "y" , right parenthesis equals 1 minus left parenthesis, 1 minus "h" Subscript, "f" , Baseline left parenthesis, "x" , "y" , right parenthesis , right parenthesis left parenthesis, 1 minus "h" Subscript, "f" , Baseline left parenthesis, negative "x" , "y" , right parenthesis , right parenthesisffx,y=1−1−hfx,y1−hf−x,y
