What is the sum of Solidat (c) that's purpose is display type, heavy duty jobs, and a hardness (brinell) is smaller than 33?
CREATE TABLE "type_metal_alloys_mentioned_in_the_uk_mo" (
  "sn_sb_pct" text,
  "liquidat_c" real,
  "solidat_c" real,
  "hardness_brinell" real,
  "purpose" text
);
SELECT SUM("solidat_c") FROM "type_metal_alloys_mentioned_in_the_uk_mo" WHERE "purpose"='display type, heavy duty jobs' AND "hardness_brinell"<33;