set u = the BinOp of (bool {});
take \/-SemiLattStr(# (bool {}), the BinOp of (bool {}) #) ; :: thesis: ( \/-SemiLattStr(# (bool {}), the BinOp of (bool {}) #) is strict & not \/-SemiLattStr(# (bool {}), the BinOp of (bool {}) #) is empty )
thus ( \/-SemiLattStr(# (bool {}), the BinOp of (bool {}) #) is strict & not \/-SemiLattStr(# (bool {}), the BinOp of (bool {}) #) is empty ) ; :: thesis: verum