$$L = \{a^i b^j c^k \mid i \le j \text{ or } (j \le i \text{ and } j = k)\}$$
I think the given language is CSL as i can break this language like this
$$L = \{a^i b^j c^k \mid i \le j \text{ and } j = k\} \cup \{a^i b^j c^k \mid j \le i \text{ and } j = k\} \cup \{a^i b^j c^k \mid i \le j \text{ and } j \le i \text{ and } j = k\}$$
Last language i,j are independent, hence DCFL.
When we take union of these languages, we get CSL.
Is my approach right?
{a^i b^j c^k | i≤j or (k=j≤i)}
from the title/rev 1-3.) $\endgroup$ – greybeard Dec 27 '16 at 12:04