ABSTRACT
Let ∅ =U − 1 ' ⊆ U 0 ' ⊆ … https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003071723/fddffade-8341-4eba-9b46-492985c90eb0/content/eq420.tif"/> be an ascending chain of subsets of spec(R) defined as follows:
U 0 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003071723/fddffade-8341-4eba-9b46-492985c90eb0/content/eq421.tif"/> is the set of all maximal elements of spec(R);
If i is not a limit ordinal then U i ' = { P ∈ spce ( R ) | P ⊂ Q ∈ spec ( R ) ⇒ Q ∈ U i-1 ' } https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003071723/fddffade-8341-4eba-9b46-492985c90eb0/content/eq422.tif"/> ;
If i is a limit ordinal then U i ' = U j<i U j ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003071723/fddffade-8341-4eba-9b46-492985c90eb0/content/eq423.tif"/> .
