鉴于:
S->AcA|BcB
A->ccBc|ABA|cc
B->c
step1
S0->S
S->AcA|BcB
A->ccBc|ABA|cc
B->c
step2 // change symbol to terminals?
S0->S
S->ABA|BBB
A->BBBB|ABA|BB
B->c
step3 // split?
S0->S
S->ABA
S->BBB
A->BBBB
A->ABA
A->BB
B->c
step4 // what to do when A->AXA?
S0->S
S->ABA
S->BBB
A->BBBB //??
A->ABA //??
A->BB //??
B->c
我不确定如何继续。