---------------------------------------------------------------------- AND_CONV (reduceLib) ---------------------------------------------------------------------- AND_CONV : conv SYNOPSIS Simplifies certain boolean conjunction expressions. LIBRARY reduce DESCRIBE If {tm} corresponds to one of the forms given below, where {t} is an arbitrary term of type {bool}, then {AND_CONV tm} returns the corresponding theorem. Note that in the last case the conjuncts need only be alpha-equivalent rather than strictly identical. AND_CONV "T /\ t" = |- T /\ t = t AND_CONV "t /\ T" = |- t /\ T = t AND_CONV "F /\ t" = |- F /\ t = F AND_CONV "t /\ F" = |- t /\ F = F AND_CONV "t /\ t" = |- t /\ t = t FAILURE {AND_CONV tm} fails unless {tm} has one of the forms indicated above. EXAMPLE #AND_CONV "(x = T) /\ F";; |- (x = T) /\ F = F #AND_CONV "T /\ (x = T)";; |- T /\ (x = T) = (x = T) #AND_CONV "(?x. x=T) /\ (?y. y=T)";; |- (?x. x = T) /\ (?y. y = T) = (?x. x = T) ----------------------------------------------------------------------