Almost finished project proposal and implemented build system.

Makefile

+
+BUILD=build/
+
+# Fix pdflatex search path
+TEXINPUTS := "$(TEXINPUTS):docs"
+TEXFLAGS  := -halt-on-error -interaction=nonstopmode -file-line-error
+TEXGREP   := grep -i ".*:[0-9]*:.*\|warning"
+
+TGT_DIR :=
+TGT_DOC :=
+
+d := docs/
+include base.mk
+include $(d)/rules.mk
+
+.PHONY: docs
+
+all: docs
+
+clean:
+	rm -rf $(CLEAN)
+
+docs: $(TGT_DOC)
+
+$(TGT_DIR):
+	mkdir -p $(TGT_DIR)
+
+$(b)%.pdf: $(d)%.tex $(TGT_DIR)
+	pdflatex $(TEXFLAGS) -output-directory `dirname $@` $< | ${TEXGREP} || true

base.mk

+b := $(BUILD)$(d)
+TGT_DIR := $(TGT_DIR) $(b)
+CLEAN := $(CLEAN) $(b)

docs/proposal.tex

@@ -15,7 +15,6 @@
 \begin{document}
 
 \maketitle
-\tableofcontents
 
 \section{Introduction}
 
@@ -57,7 +56,37 @@ TODO
 \subsubsection{Modules}
 
 \begin{itemize}
-    \item \emph{TODO}
+    \item Expressions without variables. $(3+4) \times (5+7)$
+    \item Linear expressions. $(3+2p) \times 7$
+    \item Linear expressions with absolute values. $|x-1| = 2$
+    \item Systems of linear equations (two variables).
+    $$ \
+    \begin{array}{|rcr|}
+    3x + 2y & = & 5 \\
+    2x - 3y & = & 6
+    \end{array}
+    \
+    \rightarrow
+    \
+    \begin{array}{|rcr|}
+    x + \frac{2}{3}y & = & \frac{5}{3} \\
+    x - \frac{3}{2}y & = & 3
+    \end{array}
+    \
+    \rightarrow
+    \
+    \frac{5}{3} - \frac{2}{3}y = 3 + \frac{3}{2}y
+    \
+    \rightarrow
+    \
+    \begin{array}{|rcr|}
+    x & = & 2\frac{1}{13} \\
+    y & = & -\frac{8}{13}
+    \end{array}
+    $$
+    \item Trigonometric functions.
+    \item Derivatives.
+    \item Integrals (computing antiderivates).
 \end{itemize}
 
 \subsection{Graphical user interface}

docs/rules.mk

+TGT_DOC += $(b)proposal.pdf