Start: (q_0), stack (Z_0). Accept: (q_3), stack (Z_0). This PDA accepts ( a^i b^j c^k \mid j = i + k ), with the stack keeping count of (i+k) and popping once per (b) to verify equality.
Let's do clearly:
Actually better structure:
Then (q_2): ( \delta(q_2, b, X) = (q_2, \varepsilon) ) ( \delta(q_2, \varepsilon, Z_0) = (q_3, Z_0) ) (accept when stack empty and no more (b)) : (a^2 b^5 c^3) is rejected since 5 ≠ 2+3=5 actually 5=5 ✔ so accepted. Wait j=5, i=2,k=3 sum=5, so accepted. Good. (a^2 b^4 c^3) (reject: 4≠5) Run: (q_0): read aa: stack XXZ0 ε→q1: stack XXZ0 q1: read cc: stack XXXXZ0 ε→q2: stack XXXXZ0 q2: read b (1st): stack XXXZ0 b (2nd): stack XXZ0 b (3rd): stack XZ0 b (4th): stack Z0, no more b, ε→q3 accept. Wait, that accepts even though 4≠5? That's wrong — mistake!
[ L = a^i b^j c^k \mid j = i + k ] We need ( j = i + k ) with ( i, j, k \geq 0 ) (assuming nonnegative integers unless specified otherwise, but typical problem means ( i, j, k \ge 1 ) possibly; here we'll do ( i, j, k \ge 0 ) but ( j = i+k )).