// constraints.wrm
//  @(#)constraints.wrm	1.1 4/15/97

// A constraint given on a class will be checked
// before saving an object while parsing an ace file
// if an object does not satisfy the constraint,
// you will get a parse error

// Example

// Class Paper
// Constraints "Year:1"

// this will imply that you cannot edit a paper
// that does not have a Year value, 
//  i.e. field 1 right of Year must be non void

// any acedb query LOCAL to a single object is valid
//    don t use: FIND or FOLLOW constructions