Def is a parameter that describes the DEF of a card.

Acceptable forms:

Def:300   ---exactly 300 DEF

Def:>300   ---greater than 300 DEF

Def:>=300  --greater than or equal to 300 DEF

Def:<300    ---less than 300 DEF

Def:<=300   ---less than or equal to 300 DEF

Def!:300    ----NOT 300 DEF

Spell and Trap cards (except Trap Monsters, etc.) will always test False for any of the above forms.