Need help with Expressions "Causal Reasoning"

[abd-als]

Im trying to use the expressions interpret and expression but it doesnt seem to work.

res = ai.Symbol('The horn only sounds on Sundays.') & ai.Symbol('I hear the horn.')
res
;class symai.symbol.Symbol at 0x11a6d7a10>(value=The horn only sounds on Sundays.I hear the horn.)