1: Ponders company portals embracing information technology (9)
2: Uncovered some letters written back in Sumerian epoch (4-3)
3: Cook ran; ragout spilled; one might jump to conclusions here? (8,5)
4: Child is to depart, finally (3)
5: Inciting anger in the ruler of a Utah city? (9)
6: Acid destroyed brace (5)
7: Is next to a total bust (5)
10: One-time philosophical teaching turned him to classics (13)
13: Tool placed under sack as a safety precaution (4,5)
15: Cool customers liable to be tossed? (9)
18: Others acquired skill to turn over a new leaf (7)
19: One who leads many after something irrational. (5)
20: Abstract art is just one step.(5)
22: One may be a very long time (3)