Truly declarative language?

Question

Does anyone know of a truly declarative language? The behavior I\'m looking for is kind of what Excel does, where I can define variables and formulas, and have the formula\'s re

Answer 1

You can mimic it in Ruby:

x = 10
y = 20
z = lambda { x + y }
z.call    # => 30
z = 50
z.call    # => 70

Not quite the same as what you want, but pretty close.