Hi! I am building a database with mathematical expressions. For example something like '1+x/y'. I want to try to create an index to quickly find records that match a pattern like '?a + ?b' ('1+x/y' is an example of this). Is this feasible? (the jsquery project is doing something a little like this) I do not know much about complicated indexes. I looked at the GIN index which is somehow able to index contains and contained by. For example in some way 1+x/y contains ?a+?b. I thought about creating a function in Lua to check this and create an operator class to make this work with the GIN index. Is something like that possible? Could it actually work?