Illformed AST?

[Nlits]

What is wrong with this code? Can the `{}` syntax not have idents?
    
    
    Hint: used config file 
'/home/runner/.choosenim/toolchains/nim-1.6.10/config/nim.cfg' [Conf]
    Hint: used config file 
'/home/runner/.choosenim/toolchains/nim-1.6.10/config/config.nims' [Conf]
    
.........................................................................................................
    /home/runner/VarCalc/parsers.nim(20, 19) Error: illformed AST: {"tan": tan, 
"sin": sin, "cos": cos, "log2": log2, "ceil", ceil, "floor", floor}
    
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I’m trying to put some math functions into a `Table[string, proc (f: 
SomeFloat): SomeFloat]`