# How can I understand about ZFC and Gödel's Completeness theorem [closed]

English

1　ZFC could be formulated as First order logic.

2　Gödel's Completeness theorem is a theorem within ZFC.

3　I think a lot of books about set theory is implicitly assuming Gödel's completeness theorem without proof.First I assume Gödel's completeness theorem without proof, after that will it be pfoofed?