Let G(V, E) be a directed graph, where V = {1, 2, 3, 4, 5} is the set of vertices and E is the set of directed edges, as defined by the following adjacency matrix A.

$$A[i][j] = \left\{ {\matrix{ {1,} & {1 \le j \le i \le 5} \cr {0,} & {otherwise} \cr } } \right.$$

A[i][j] = 1 indicates a directed edge from node i to node j. A directed spanning tree of G, rooted at r $$\in$$ V, is defined as a subgraph T of G such that the undirected version of T is a tree, and T contains a directed path from r to every other vertex in V. The number of such directed spanning trees rooted at vertex 5 is _____________.

Which one of the following statements is TRUE?

Consider the augmented grammar with {+, *, (, ), id} as the set of terminals.

S' $$\to$$ S

S $$\to$$ S + R | R

R $$\to$$ R * P | P

P $$\to$$ (S) | id

If I₀ is the set of two LR(0) items {[S' $$\to$$ S.], [S $$\to$$ S. + R]}, then goto(closure(I₀), +) contains exactly _________ items.

Consider the following grammar along with translation rules.

S $$\to$$ S₁ # T {S.val = S₁.val * T.val}

S $$\to$$ T {S.val = T.val}

T $$\to$$ T₁ %R {T.val = T₁.val $$ \div $$ R.val}

T $$\to$$ R {T.val = R.val}

R $$\to$$ id {R.val = id.val}

Here # and % are operators and id is a token that represents an integer and id.val represents the corresponding integer value. The set of non-terminals is {S, T, R, P} and a subscripted non-terminal indicates an instance of the non-terminal. Using this translation scheme, the computed value of S.val for root of the parse tree for the expression 20#10%5#8%2%2 is ___________.