Calculus
- Calculus::=Net{Differential_Calculus, Operational_Calculus, Ordinary_differential_equations, Partial_differential_equations,...} .
- Differential_Calculus::=
Net{
R::semi-ring. F::@(R->R). D::F<>->F. DF::=pre(D).
- For x,y,z:R, f, g, h :DF.
...
- For x:variable(R), e:expression(R), D[x](e) ::=D(map[x:R](e)).
Thurston 94, Hugh Thurston, What is Wrong With the Definition of dy/dx, Am Math Monthly V101n9(Nov 94)pp855-857
- For f,g, d f/d g::F = D(f)/D(G).
Convention: the variables x,y, and z are used to represent elements of
F and in particular, x is often used as the Id function.
- |-Id in DF and D Id = 1.
- (above)|-D[x](x) = d x/d x=fun[x]1.
- |-For a:R, D[x](a)=[x]0.
- (above)|-D[x](a) = d a/d x=fun[x]0.
- |-D(f + g)= D(f) + D(g),
- |-D(f * g)= D(f) * g + f * D(g),
- |-D(f o g)= D(g) * (D(f) o g).
- (above)|-D(f ; g)=D(f) * (f ; D(g)).
- (above)|-For a,b:R, D(a * f + c)=a * D(f).
- (above)|-D[x](x^2)=fun[x]2*x, |-D[x](x^3)=fun[x]3*x^2, ... .
- (above)|-For n , D(_^n)=n*(_^(n-1)).
- (above)|-For non_zero_integer n , D[x](x^n)=fun[x]n*x^(n-1).
- (above)|-D[x]f(g(x))=fun[x] ( D(g)(x) * (D(f))(g(x))).
- (above)|-if R in Field then D/f = 1/( D(f) o /f ).
}=::
Differential_Calculus.
- Operational_Calculus::=
Net{
- R::semi-ring.
- F::@(R->R).
- n::=dimension(R).
Assume n different and non-overlapping step operators.
- D::F<>->F.
- DF::=pre(D).
- E::1..n->(F<>->F)= fun[i](fun[f](fun[r](f(r+δ[i])).
- Δ::= E - 1.
- Δ_upside_down::= 1 - /E.
- |-semi_ring( generated=>Net{D, F, Δ, Δ_upside_down, ...}.
- (above)|-if n=1, ... then E= e^(h D).
}=::
Operational_Calculus.
. . . . . . . . . ( end of section Calculus) <<Contents | End>>
Notes on MATHS Notation
Special characters are defined in
[ intro_characters.html ]
that also outlines the syntax of expressions and a document.
Proofs follow a natural deduction style that start with
assumptions ("Let") and continue to a consequence ("Close Let")
and then discard the assumptions and deduce a conclusion. Look
here
[ Block Structure in logic_25_Proofs ]
for more on the structure and rules.
The notation also allows you to create a new network of variables
and constraints. A "Net" has a number of variables (including none) and
a number of properties (including none) that connect variables.
You can give them a name and then reuse them. The schema, formal system,
or an elementary piece of documentation starts with "Net" and finishes "End of Net".
For more, see
[ notn_13_Docn_Syntax.html ]
for these ways of defining and reusing pieces of logic and algebra
in your documents. A quick example: a circle = Net{radius:Positive Real, center:Point}.
For a complete listing of pages in this part of my site by topic see
[ home.html ]
Notes on the Underlying Logic of MATHS
The notation used here is a formal language with syntax
and a semantics described using traditional formal logic
[ logic_0_Intro.html ]
plus sets, functions, relations, and other mathematical extensions.
For a more rigorous description of the standard notations
see
- STANDARD::= See http://www.csci.csusb.edu/dick/maths/math_11_STANDARD.html
Glossary
- above::reason="I'm too lazy to work out which of the above statements I need here", often the last 3 or 4 statements.
The previous and previous but one statments are shown as (-1) and (-2).
- given::reason="I've been told that...", used to describe a problem.
- given::variable="I'll be given a value or object like this...", used to describe a problem.
- goal::theorem="The result I'm trying to prove right now".
- goal::variable="The value or object I'm trying to find or construct".
- let::reason="For the sake of argument let...", introduces a temporary hypothesis that survives until the end of the surrounding "Let...Close.Let" block or Case.
- hyp::reason="I assumed this in my last Let/Case/Po/...".
- QED::conclusion="Quite Easily Done" or "Quod Erat Demonstrandum", indicates that you have proved what you wanted to prove.
- QEF::conclusion="Quite Easily Faked", -- indicate that you have proved that the object you constructed fitted the goal you were given.
- RAA::conclusion="Reducto Ad Absurdum". This allows you to discard the last
assumption (let) that you introduced.