Context:
	{Context} 'If' '(' check=FeatureExpression ')' 'exists' '{'
		steps+=Steps+
	'}'
	(-> 'else' '{' elseSteps+=Steps+ '}')?
;

FeatureExpression:
	MultiFeature
;

SingleFeature:
	'Feature' name=Description
;

MultiFeature:
	FeatureAndFeature | FeatureOrFeature
;

FeatureOrFeature returns MultiFeature:
	FeatureAndFeature ({FeatureOrFeature.left=current} 'OR' right=FeatureAndFeature)*
;

FeatureAndFeature returns MultiFeature:
	Primary ({FeatureAndFeature.left=current} 'AND' right=Primary)*
;

Primary returns MultiFeature:
	SingleFeature | '(' FeatureOrFeature ')'
;