| Class Summary | 
| SubArrayElement | This class corresponds to the substitution of xxxelementswith a 
 formula. | 
| SubArrayElementSingle | This class corresponds to the substitution of xxxelementswith a 
 formula. | 
| SubArrayLength | This class corresponds to the substitution of arraylengthwith a 
 formula. | 
| SubForm | This class corresponds to the substitution of a formula by another. | 
| SubInstancesSet | This class corresponds to the substituion of instanceswith:instances \/ f. | 
| SubInstancesSingle | This class corresponds to the substituion of instanceswithinstances \/ {f}corresponding to an instance creation. | 
| SubMemberField | This class implements a substitution of a member field abya <+ { b |-> c }corresponding to an affectation of a new value
 for a given instance. | 
| SubTmpVar | This class corresponds to the substitution of a tempory variable with a 
 formula. | 
| SubTypeofSet | This interface describes a substitution of typeofbytypeof <+ f * {t} | 
| SubTypeofSingle | This interface describes a substitution of typeofbytypeof <+ {f |-> t} |