-- input --
= ^income
    (liabilities:tax)  *.33

= expenses:gifts
    budget:gifts  *-1
    assets:budget  *1

= income:salary
    budget:savings  (amount * 0.5)
-- expect --
Journal
  AutomatedTransaction j:1:1-4:0
    Expr: "^income"
    Posting j:2:1-4:0
      Type: unbalanced virtual
      Account j:2:6-2:21
        SubAccount: "liabilities" j:2:6-2:17
        SubAccount: "tax" j:2:18-2:21
      Amount j:2:25-2:25
        Quantity: 0.33
        Commodity: ""
        CommodityPos: Before
        HasSpace: false
        IsExpr: true
        Precision: 2
        Decimal: "."
  BlankLine j:4:0-4:1
  AutomatedTransaction j:4:1-8:0
    Expr: "expenses:gifts"
    Posting j:5:1-6:1
      Account j:5:5-5:17
        SubAccount: "budget" j:5:5-5:11
        SubAccount: "gifts" j:5:12-5:17
      Amount j:5:20-5:20
        Quantity: -1
        Commodity: ""
        CommodityPos: Before
        HasSpace: false
        IsExpr: true
        Precision: 0
        Decimal: "."
    Posting j:6:1-8:0
      Account j:6:5-6:18
        SubAccount: "assets" j:6:5-6:11
        SubAccount: "budget" j:6:12-6:18
      Amount j:6:21-6:21
        Quantity: 1
        Commodity: ""
        CommodityPos: Before
        HasSpace: false
        IsExpr: true
        Precision: 0
        Decimal: "."
  BlankLine j:8:0-8:1
  AutomatedTransaction j:8:1-10:1
    Expr: "income:salary"
    Posting j:9:1-10:1
      Account j:9:5-9:19
        SubAccount: "budget" j:9:5-9:11
        SubAccount: "savings" j:9:12-9:19
      Amount j:9:21-10:0
        Quantity: 0
        Commodity: ""
        CommodityPos: Before
        HasSpace: false
        IsExpr: true
        Expr: "amount * 0.5"
        Precision: 0
        Decimal: "."