implement case when statement with dict items and two column values, return true if match

is there any way we can compare dictionary items with two column values in the dataframe?

example:

dic = [ (a,1),(b,2),(c,3)]

below is the dataframe, input_dataframe having only name, id column

output_dataframe has flag column. it compares both a&b columns, if both values are present in dict items, true is returned in "flag" column

I had implemented case when as shown below,

df = df.withColumn( flag, when(struct(col("a"), col("b")).isin(dic), lit('True')) .otherwise(lit("False")) )

but its giving the error as

ERROR occurred while validating: user_dw_pnldetail Error: [UNSUPPORTED_FEATURE.LITERAL_TYPE] The feature is not supported: Literal for '[a, 1]' of class java.util.ArrayList. SQLSTATE: 0A000

can someone help me to fix the error