Constrained argumentation frameworks (CAF) generalize Dung's frameworks by allowing additional constraints on arguments to be taken into account in the definition of acceptability of arguments. These constraints are expressed by means of a logical formula which is added to Dung's framework. The resulting system captures several other extensions of Dung's original system. To determine if a set of arguments is credulously inferred from a CAF, the notion of dialectical proof (alternating pros and cons arguments) is extended for Dung's frameworks in order to respect the additional constraint. The new constrained dialectical proofs are computed by using Answer Set Programming.