Compiler

Question

$S\rightarrow AaB$

$A\rightarrow ab|a$

$B\rightarrow b$

Above grammar is

a)Not LR(0)

b)Not LR(0) but SLR(1),CLR(1)

Comments

i am getting SLR(1) but not CLR(1) and LR(0) so option a) i guess.

---

what is the answer?

---

@Abhinav Gupta

i am getting SLR(1) but not CLR(1) and LR(0)

is it possibe that grammar is SLR(1) but not CLR(1)?

@srestha,

option B) is correct, it is not LR(0)(due to SR conflict), but it is SLR(1) and so also CLR(1), and option B) implies option A).

so both option A) and B) are correct. 

---

Yes both are correct but B is more accurate.

---

there is SR conflict...in second state...of A->ab/a  not LR(0)....but SLR(1) and then definite LR(1)

---

guys

there is SR conflict

right?

if there is SR conflict for SLR, then there is SR conflict for LALR

So, how, it could be SLR(1), ,LR(1)

Only this point I was missing, and that is why I answered A)

Plz tell me where I was wrong?

---

@srestha,

for SLR(1), there is no SR conflict

the state in which you are thinking there is SR conflict, actually there is no SR conflict.

the shift is happening on 'b' and reduce is happening on follow(A)='a', since both shift and reduce are happening on a different symbol, it is not an SR conflict in SLR(1)

---

sresta

for LALR we reduce the production corresponding to look_ahead