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Description
Lecture Notes on the Lambda CalculusThis is a set of lecture notes that developed out of courses on the lambda calculus that the author taught at the University of Ottawa in 2001 and at Dalhousie University in 2007 and 2013. Topics covered in these notes include the untyped lambda calculus, the Church Rosser theorem, combinatory algebras, the simply typed lambda calculus, the Curry Howard isomorphism, weak and strong normalization, polymorphism, type inference, denotational semantics,
This is a set of lecture notes that developed out of courses on the lambda calculus that the author taught at the University of Ottawa in 2001 and at Dalhousie University in 2007 and 2013. Topics covered in these notes include the untyped lambda calculus, the Church-Rosser theorem, combinatory algebras, the simply-typed lambda calculus, the Curry-Howard isomorphism, weak and strong normalization, polymorphism, type inference, denotational semantics, complete partial orders, and the language PCF.
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4.7 ★★★★★
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Product Reviews
★★★★★ 5
Great replacement micro needling cartridges.
Picked today up for replacements for my Dr Pen micro needler.
They arrived individually sealed, ready for use. They appear to be compatible good quality product just like my originals. Love the price point and savings.
They fit my device perfectly.
These arrived at the Dr Pen cartridge box although do not have Dr Pen brand on cartridges appear high-quality similar in packaging of the originals. They do not have the pen, cap safety guard, but that's really not a needed part of the product.
Make sure to verify you have the right device.
Be aware they do not fit correctly in M8 devices.
Great value for the money you get 21 piece micro, needling cartridges, various needle styles. The kit comes with 36 needle, 12 needle and nano cartridges.
I have already used the Nano cartridge and they are super comparable to original cartridges quality, They do not drag on the skin easily move and dispense face serum product.
So far, I've been super happy with the replacements.
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Reviewed in the United States on May 29, 2026
★★★★★ 5
21 Piece Pen Cartridges
This 21 piece microneedling cartridge set is an excellent value and gives a lot of versatility for different skincare needs. I really like that it includes three different tip styles: nano, 12 pin, and 36 pin. There are 7 of each variety included, which makes it easy to customize treatments depending on what area I’m focusing on and how gentle or intensive I want the session to be.
The cartridges fit my Dr Pen device well and feel securely attached during use. Everything came individually packaged and clean, which is important for at home microneedling routines. The nano tips are great for product infusion and glow-focused treatments, while the 12 and 36 pin options work well for more targeted skin texture care. Overall, this is a convenient and affordable replacement set that’s perfect for anyone wanting multiple cartridge options in one package.
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Reviewed in the United States on May 22, 2026
★★★★★ 4
Wish I Knew if it is Surgical Grade Steel
I have a Dr. Pen A6, and these non-OEM cartridges are a great value. You receive twenty-one cartridges in various sizes, and each cartridge is individually wrapped.
These pins come in three sizes: thirty-six pin, twelve pin, and nano. I had no issue inserting the cartridge and locking it into place, and I didn't notice any wiggling or looseness. The pins were sharp and did not tear or drag on my skin. Of course, you will see small pinpricks where you have treated.
One thing I would like to know is whether these are made with surgical grade steel. I would prefer that they are, but I don't see that information anywhere in the listing. That said, I didn't notice any unusual irritation.
I now have a good variety of cartridges to be more consistent with my pen usage. I will update this review if I notice anything related to the steel used.
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Reviewed in the United States on May 19, 2026
★★★★★ 5
Perfect for Husbands but Wives may Enjoy Reading it Too!
For a long time I've wondered what my love language is in particular because they all sound good to me. I love receiving stuffed animals from my husband so maybe it is gifts. But then I also adore undivided attention when we watch movies nearly every night, so maybe it is quality time. When my husband empties the dishwasher that is good so maybe it is acts of service. Well how about a compliment, that is nice too. I think I'm greedy, I want it all. lol So don't think your wife will only like just one love language. Maybe she wants touch, quality time and acts of service too.
This book explains what the typical differences are in what men and women want in regards to love languages. It also wisely explains how to apologize to a woman in a sincere way that will make her melt. It deals with anger and women want less of that!
At the end of the book there are two tests, one for him, one for her. You can then figure out what each other's love languages are. As the books says, sometimes you are bilingual. Also there are various dialects.
This book also makes you realize why sometimes the love language works and at other times it does not get the points you think you are getting. Like when a woman is really busy, some things mean more than others. While she's in the kitchen she might want help with the kids instead of touch or when she is feeling down she might want a compliment to make her feel appreciated.
So I think learn all the love languages and use them wisely. I'm a fan! Any man who adds these languages to his skill set is going to be way more desired than usual. Women pay attention and this is a way of getting your point across. Oh and at the end of the chapters there is an easy "phrase book" so you get tips on specific things you can do to speak each language.
I'm giving this book to my husband and I really hope he reads it! I'm also happy I read it because I've got myself more figured out. To my husband I say more love languages please!!!!
~The Rebecca Review
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Reviewed in the United States on August 18, 2024
★★★★★ 5
Good book
Good book
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Reviewed in the United States on February 23, 2026