Solve an alien message

Question

The following is a puzzle that I was given back in the early 1970’s. Everything that follows this introductory paragraph is part of the puzzle I was given. That includes all of the paragraphs below statement 14. The paragraphs below are kind of dated. I changed a couple of letters in line 14 because I think some measurements might now be more precise than whenever this puzzle was created. I hope I didn't make any typos.

1. A.B.C.D.E.F.G.H.I.J.K.L.M.N.O.P.Q.R.S.T.U.V.W.X.Y.Z.
2. AA,B;AAA,C;AAAA,D;AAAAA,E;AAAAAA,F;AAAAAAA,G;AAAAAAAA,H; AAAAAAAAA,I;AAAAAAAAAA,J.
3. AKALB;AKAKALC;AKAKAKALD.AKALB;BKALC;CKALD;DKALE. BKELG;GLEKB.FKDLJ;JLFKD.
4. CMALB;DMALC;IMGLB.
5. CMNLC;NKNLN.DMDLN;EMELN.
6. JLAN;JKALAA;JKBLAB;AAKALAB.JKJLBN;JKJKJLCN.FNKGLFG.
7. BPCLF;EPBLJ;FPJLFN.
8. FQBLC;JQBLE;FNQFLJ.
9. CRBLI;BRELCB
10. JPJLJRBLSLANN;JPJPJLJRCLTLANNN.JPSLT;JPTLJRD.
11. AQJLU;UQJLAQSLV.
12. ULWA;UPBLWB;AWDMALWDLDPU.VLWNA;VPCLWNC. VQJLWNNA;VQSLWNNNA.JPEWFGHLEFWGH;SPEWFGHLEFGWH.
13. GIWIHYHN;TKCYT.ZYCWADAF.
14. DPZPWNHFGRCQC.

Much speculation has recently been devoted to the possibility of intelligence elsewhere in the universe. So far no evidence exists to indicate that there is intelligent life other than us. If intelligent life does exist, the problem arises of how to contact it so that the culture receiving its message will acknowledge it.

For instance, consider Earth for a moment. If we were to send a message in some language what language would we choose? Since there are some several thousand languages and dialects spoken it is easy to see the problem involved.

The above message comes from somewhere within our solar system. Its creator felt it had circumvented the above problem by assuming it had chosen a language that could be universally understood within our solar system. See if you can solve this code. If you can you must then say where the message came from, which indicated you have totally solved the puzzle. Here are some rules to follow:

The numbers 1. through 14. merely indicate a statement of lettered symbols. They are not part of the code. You must proceed in the numbered sequence or the code will be impossible to solve. A comma indicates a slight pause, a semicolon a greater pause, and a period the end of a statement. This message can only come from one place in the solar system and statement 14. represents it.

Answer 1

The lines define a base-10 number system and some operations.
Line 1 lays out the symbols which can be used.
Line 2 shows that B through J are two through ten times A, which is probably 1.
Line 3 introduces K and L, with 1K1L2, 1K1K1L3, 2K1L3, etc. K must be addition and L is equality.
Line 4 had 3M1=2, 4M1=3, 9M7=2. M is subtraction.
Line 5 states that 3-N=3, N+N=N, and 4-4=N. N must be 0.
Line 6 shows that the number system is in base ten, because J (ten) is written as 10.
Line 7 defines P as multiplication: 2*3=6, 5*2=10, 6*10=60.
Similarly, Line 8 makes Q be division.
Line 9 has 3R2=9 and 2R5=32. R is exponentiation.
Line 10 has S=100 and T=1000.
Line 11 has U=1/10 and V=1/100.
Line 12 introduces W as the decimal point, because U=0.1 and V=0.01.
Line 13 states that 79.98Y80, 1000+3Y1000, and ZY3.1416. Y must be approximately equal, and Z is pi.
Line 14 is 4*pi*0.0867^3/3. This is the formula for the volume of a sphere with a radius of 0.0867. The radius of Saturn is 0.0867 times the radius of the Sun, so the signal must be from Saturn.