[9.3.] “Places and Times.” (Ch.10:4)

 

We can translate sentences that refer to places into the symbolization of relational predicate logic:

 

E.g. (from your textbook, p.230):

 

“Somewhere, the streets are all paved with gold.” =

 

There exists a place where all streets are paved with gold.  =

 

Px: x is a place

Sxy: x is a street in y

Gx: x is paved with gold

 

($x)[Px · (y)(Syx É Gy)]

 

 

We can also translate sentences that refer to times into the symbolization of relational predicate logic:

 

“The sun never sets on the British Empire.”[1]  =

 

There is no such thing as a time at which the sun sets on the British Empire.  =

 

Tx: x is a time

Sxyz: x sets on y at z

s: the sun

b: the British Empire

 

~($x)(Tx · Ssbx)

 

 

Exercise 10-4

·         do all of these; we’ll work through the odds next time

 

Stopping point for Friday April 11. For next time, do ex.10-4 (#5-15 only), and read Ch.10:5 (pp.231-34).