单项选择题
公式"x ( F(x,y,z ) → "y ( G(x,y,z) → "z H(x,y,z) ) )的前束范式为
A、"x$y$z (F(x,t,w) → ( G(x,y,w ) → H(x,y,z) ) )
B、$x$y$z (F(x,t,w) → ( G(x,y,w ) → H(x,y,z) ) )
C、"x"y$z (F(x,t,w) → ( G(x,y,w ) → H(x,y,z) ) )
D、"x$y"z (F(x,t,w) → ( G(x,y,w ) → H(x,y,z) ) )