Added simple examples

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+module mulmat
+
+/*
+Matrix Multiplication.
+
+This  program  performs  matrix multiplication  on matrices of  integers.
+Lists are used to simulate matrices
+The  initial matrices  (Mat1 & Mat2) can have  arbitrary size (Size). The
+second matrix is transposed  first, in order to avoid traversing a matrix
+by column, which is very inefficient. The result of the program shows the
+initial  matrices  and the  resulting matrix. Run  the program  with  the
+"Show Constructors" option on (Application Options).
+*/
+
+import StdInt, StdString
+
+::Row		:== [Int]	// A row is a list of integers.
+::Col		:== [Int]	// A column is a list of integers.
+::Mat		:== [Row]	// A matrix is a list of rows.
+::TMat		:== [Col]	// A transposed matrix is a list of columns.
+::Index_new	:== Int		// An index is an integer.
+
+Size :== 6	// The size of the matrices.
+
+//	The initial matrices
+
+Mat1::Mat
+Mat1 	=	[[  1, 2, 3, 4, 5, 6 ]		// 
+			,[  0, 1, 2, 3, 4, 5 ]		// 
+			,[ -1, 0, 1, 2, 3, 4 ]		//	The product of these matrices:
+			,[ -2,-1, 0, 1, 2, 3 ]		// 
+			,[ -3,-2,-1, 0, 1, 2 ]		// 
+			,[ -4,-3,-2,-1, 0, 1 ]]		//		[ 0 -9  0  5  1  7 ]
+										//		[ 0 -8 -1  4  1  6 ]
+Mat2::Mat								//		[ 0 -7 -2  3  1  5 ]
+Mat2 	= 	[[  0, 1, 0, 0, 0,-1 ]		//		[ 0 -6 -3  2  1  4 ]
+			,[  1, 0, 1, 1, 0, 1 ]		//		[ 0 -5 -4  1  1  3 ]
+			,[ -1, 0, 1,-1, 0, 0 ]		// 		[ 0 -4 -5  0  1  2 ]
+			,[ -1,-1,-1, 0,-1, 0 ]		// 
+			,[  1, 0, 1, 0, 1, 0 ]		// 
+			,[  0,-1,-1, 1, 0, 1 ]]		// 
+
+
+//	Multiplying two matrices.
+
+MulMat::Mat Mat -> Mat
+MulMat m1 m2   =  TMulMat m1 (Transpose m2)
+
+TMulMat::Mat TMat  -> Mat
+TMulMat [r] m2    =  [ MulRow r m2 ]
+TMulMat [r:rs] m2 =  [ MulRow r m2 : TMulMat rs m2 ]
+
+MulRow::Row TMat -> Row
+MulRow r [c]    =  [ Inprodukt r c ]
+MulRow r [c:cs] =  [ Inprodukt r c : MulRow r cs ]
+
+Inprodukt::Row Col  -> Int
+Inprodukt [] []         =	0
+Inprodukt [a:as] [b:bs] =	a * b  +  Inprodukt as bs 
+
+//	Transposing a matrix.
+
+Transpose::Mat -> TMat
+Transpose m   =  Transp m 1
+
+Transp::Mat Index_new -> TMat
+Transp m i	| i == Size =  [ Column m i ]
+						=  [ Column m i : Transp m (i + 1) ]
+
+Column::Mat Index_new -> Col
+Column [] i      =  []
+Column [r:rs] i  =  [ Select r i : Column rs i ]
+
+Select::Row Index_new -> Int
+Select [a:as] 1  =  a
+Select [a:as] i  =  Select as (i - 1)
+
+//	The Start rule: show the initial matrices and their product.
+
+Start::(Mat,String,Mat,String,Mat)
+Start 	= (m1,"\ntimes\n",m2,"\nbecomes\n",MulMat m1 m2)
+where 
+  	m1	= Mat1; m2 = Mat2
+  			 
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