What is the short name having video of 720p and programming of Main KSTC-TV programming?
CREATE TABLE "digital_channels" (
  "channel" real,
  "station" text,
  "video" text,
  "aspect" text,
  "psip_short_name" text,
  "programming" text
);
SELECT "psip_short_name" FROM "digital_channels" WHERE "video"='720p' AND "programming"='main kstc-tv programming';