jr Jf - x i- e • *(.v, y. y'\ (2)
v(.v) v[.v t: £(x. v’, r’)) + ff • rf(x, v, y)
=>
- v(x)+ep(x,y,y'}, (4)
~ *(i, v\ v')~ i§|.r, v,y)
Jish f/‘[jr, v(.v\ y’(x$& = J F[x,y(x)+ep(x,y,y\y'(x)+£p{xty\y'%Ix
= A%, + S
B
H