@Override
		public boolean equals(Object obj) {
			if ( this==obj ) return true;
			if ( !(obj instanceof AND) ) return false;
			AND other = (AND)obj;
			return Arrays.equals(this.opnds, other.opnds);
		}
A semantic context which is true whenever none of the contained contexts
is false.
runtime/Java/src/org/antlr/v4/runtime/atn/SemanticContext.java