An approchable task for our tutorial

src/ast/expressions/AndExpression.java

src/ast/expressions/BooleanExpression.java

src/ast/expressions/EqualsExpression.java

src/ast/expressions/NotExpression.java

src/ast/expressions/Operator.java

src/ast/expressions/OrExpression.java

src/ast/expressions/Type.java

src/ast/expressions/XorExpression.java